ありがとうございます。遅くなり申し訳ありません。

実はその後7.10をクリーンインストールしてみました。
それでもだめだったため、試みにnetwork managerを外してみました。
結果、残念ながら、若干ですが状況が悪化していまいました。

現在は、再起動した後、以下の手順をふまないと接続できるようになりません。

sudo ifdown ath0
sudo ifup ath0
sudo ifdown ath0
sudo ifup ath0
sudo ifdown eth0

ath0のdown/up1回では、"ネットワークの監視"のアンテナ（？）が立ちません。
もう1回down/upすると、アンテナが立ちますが、ルータにpingが通りません。
最後にifdown eth0をすると、普通にインターネットまで接続できるようになります。

さて、dmesgについてですが、dmesgコマンドはifdown eth0の後実行したのでよいのでしょうか？
出力は出たのですが、全体ではかなり長く、はりつけてよいものか迷いました。
はりつけてよいのでしょうか？

無線LANの暗号化はWPA-PSK-AESです。
固定アドレスとしています（ルータのDHCPも切っています）。
7.10にするまでは問題なかった設定ですが、問題がある可能性があるでしょうか。
（試してみればよいのですが、今すぐは時間がとれません）

指示の通り、dmesgの結果を貼り付けます。

tn@TPA:~$ sudo ifdown ath0
[sudo] password for tn:
tn@TPA:~$ sudo ifup ath0
tn@TPA:~$ sudo ifdown ath0
tn@TPA:~$ sudo ifup ath0
tn@TPA:~$ dmesg
[    0.000000] Linux version 2.6.22-14-generic (buildd@palmer) (gcc version 4.1.3 20070929 (prerelease) (Ubuntu 4.1.2-16ubuntu2)) #1 SMP Sun Oct 14 23:05:12 GMT 2007 (Ubuntu 2.6.22-14.46-generic)
[    0.000000] BIOS-provided physical RAM map:
[    0.000000]  BIOS-e820: 0000000000000000 - 000000000009f000 (usable)
[    0.000000]  BIOS-e820: 000000000009f000 - 00000000000a0000 (reserved)
[    0.000000]  BIOS-e820: 00000000000dc000 - 0000000000100000 (reserved)
[    0.000000]  BIOS-e820: 0000000000100000 - 000000002f6e0000 (usable)
[    0.000000]  BIOS-e820: 000000002f6e0000 - 000000002f6f7000 (ACPI data)
[    0.000000]  BIOS-e820: 000000002f6f7000 - 000000002f6f9000 (ACPI NVS)
[    0.000000]  BIOS-e820: 000000002f700000 - 0000000030000000 (reserved)
[    0.000000]  BIOS-e820: 00000000fec00000 - 00000000fec10000 (reserved)
[    0.000000]  BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
[    0.000000]  BIOS-e820: 00000000ff800000 - 0000000100000000 (reserved)
[    0.000000] 0MB HIGHMEM available.
[    0.000000] 758MB LOWMEM available.
[    0.000000] Entering add_active_range(0, 0, 194272) 0 entries of 256 used
[    0.000000] Zone PFN ranges:
[    0.000000]   DMA             0 ->     4096
[    0.000000]   Normal       4096 ->   194272
[    0.000000]   HighMem    194272 ->   194272
[    0.000000] early_node_map[1] active PFN ranges
[    0.000000]     0:        0 ->   194272
[    0.000000] On node 0 totalpages: 194272
[    0.000000]   DMA zone: 32 pages used for memmap
[    0.000000]   DMA zone: 0 pages reserved
[    0.000000]   DMA zone: 4064 pages, LIFO batch:0
[    0.000000]   Normal zone: 1485 pages used for memmap
[    0.000000]   Normal zone: 188691 pages, LIFO batch:31
[    0.000000]   HighMem zone: 0 pages used for memmap
[    0.000000] DMI present.
[    0.000000] ACPI: RSDP signature @ 0xC00F7020 checksum 0
[    0.000000] ACPI: RSDP 000F7020, 0024 (r2 IBM   )
[    0.000000] ACPI: XSDT 2F6E9B7E, 0054 (r1 IBM    TP-1U        1550  LTP        0)
[    0.000000] ACPI: FACP 2F6E9C00, 00F4 (r3 IBM    TP-1U        1550 IBM         1)
[    0.000000] ACPI Warning (tbfadt-0442): Optional field "Gpe1Block" has zero address or length: 000000000000102C/0 [20070126]
[    0.000000] ACPI: DSDT 2F6E9DE7, CFC2 (r1 IBM    TP-1U        1550 MSFT  100000E)
[    0.000000] ACPI: FACS 2F6F8000, 0040
[    0.000000] ACPI: SSDT 2F6E9DB4, 0033 (r1 IBM    TP-1U        1550 MSFT  100000E)
[    0.000000] ACPI: ECDT 2F6F6DA9, 0052 (r1 IBM    TP-1U        1550 IBM         1)
[    0.000000] ACPI: TCPA 2F6F6DFB, 0032 (r1 IBM    TP-1U        1550 PTL         1)
[    0.000000] ACPI: APIC 2F6F6E2D, 005A (r1 IBM    TP-1U        1550 IBM         1)
[    0.000000] ACPI: BOOT 2F6F6FD8, 0028 (r1 IBM    TP-1U        1550  LTP        1)
[    0.000000] ACPI: PM-Timer IO Port: 0x1008
[    0.000000] ACPI: Local APIC address 0xfee00000
[    0.000000] ACPI: LAPIC (acpi_id[0x01] lapic_id[0x00] enabled)
[    0.000000] Processor #0 6:9 APIC version 20
[    0.000000] ACPI: LAPIC_NMI (acpi_id[0x01] high edge lint[0x1])
[    0.000000] ACPI: IOAPIC (id[0x01] address[0xfec00000] gsi_base[0])
[    0.000000] IOAPIC[0]: apic_id 1, version 32, address 0xfec00000, GSI 0-23
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 dfl dfl)
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level)
[    0.000000] ACPI: IRQ0 used by override.
[    0.000000] ACPI: IRQ2 used by override.
[    0.000000] ACPI: IRQ9 used by override.
[    0.000000] Enabling APIC mode:  Flat.  Using 1 I/O APICs
[    0.000000] Using ACPI (MADT) for SMP configuration information
[    0.000000] Allocating PCI resources starting at 40000000 (gap: 30000000:cec00000)
[    0.000000] Built 1 zonelists.  Total pages: 192755
[    0.000000] Kernel command line: root=UUID=19084c41-ddda-411d-82e2-3503f87c5344 ro quiet splash locale=ja_JP
[    0.000000] mapped APIC to ffffd000 (fee00000)
[    0.000000] mapped IOAPIC to ffffc000 (fec00000)
[    0.000000] Enabling fast FPU save and restore... done.
[    0.000000] Enabling unmasked SIMD FPU exception support... done.
[    0.000000] Initializing CPU#0
[    0.000000] PID hash table entries: 4096 (order: 12, 16384 bytes)
[    0.000000] Detected 1096.498 MHz processor.
[    3.337054] Console: colour VGA+ 80x25
[    3.337441] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
[    3.338071] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
[    3.368987] Memory: 758412k/777088k available (2015k kernel code, 18100k reserved, 916k data, 364k init, 0k highmem)
[    3.369003] virtual kernel memory layout:
[    3.369005]     fixmap  : 0xfff4d000 - 0xfffff000   ( 712 kB)
[    3.369007]     pkmap   : 0xff800000 - 0xffc00000   (4096 kB)
[    3.369009]     vmalloc : 0xf0000000 - 0xff7fe000   ( 247 MB)
[    3.369011]     lowmem  : 0xc0000000 - 0xef6e0000   ( 758 MB)
[    3.369014]       .init : 0xc03e3000 - 0xc043e000   ( 364 kB)
[    3.369016]       .data : 0xc02f7d26 - 0xc03dce84   ( 916 kB)
[    3.369018]       .text : 0xc0100000 - 0xc02f7d26   (2015 kB)
[    3.369023] Checking if this processor honours the WP bit even in supervisor mode... Ok.
[    3.369079] SLUB: Genslabs=22, HWalign=64, Order=0-1, MinObjects=4, CPUs=1, Nodes=1
[    3.449026] Calibrating delay using timer specific routine.. 2194.57 BogoMIPS (lpj=4389158)
[    3.449061] Security Framework v1.0.0 initialized
[    3.449070] SELinux:  Disabled at boot.
[    3.449092] Mount-cache hash table entries: 512
[    3.449268] CPU: After generic identify, caps: a7e9fbbf 00000000 00000000 00000000 00000180 00000000 00000000
[    3.449286] CPU: L1 I cache: 32K, L1 D cache: 32K
[    3.449290] CPU: L2 cache: 1024K
[    3.449294] CPU: After all inits, caps: a7e9fbbf 00000000 00000000 00002040 00000180 00000000 00000000
[    3.449308] Compat vDSO mapped to ffffe000.
[    3.449323] Checking 'hlt' instruction... OK.
[    3.465146] SMP alternatives: switching to UP code
[    3.465357] Freeing SMP alternatives: 11k freed
[    3.465736] Early unpacking initramfs... done
[    4.018064] ACPI: Core revision 20070126
[    4.018267] ACPI: Looking for DSDT in initramfs... error, file /DSDT.aml not found.
[    4.036098] CPU0: Intel(R) Pentium(R) M processor 1100MHz stepping 05
[    4.036131] Total of 1 processors activated (2194.57 BogoMIPS).
[    4.036268] ENABLING IO-APIC IRQs
[    4.036464] ..TIMER: vector=0x31 apic1=0 pin1=2 apic2=-1 pin2=-1
[    4.180401] Brought up 1 CPUs
[    4.180548] Booting paravirtualized kernel on bare hardware
[    4.180610] Time: 21:45:06  Date: 10/13/107
[    4.180642] NET: Registered protocol family 16
[    4.180751] EISA bus registered
[    4.180764] ACPI: bus type pci registered
[    4.181013] PCI: PCI BIOS revision 2.10 entry at 0xfd8c8, last bus=5
[    4.181017] PCI: Using configuration type 1
[    4.181021] Setting up standard PCI resources
[    4.185174] ACPI: EC: Found ECDT
[    4.316929] ACPI: Interpreter enabled
[    4.316933] ACPI: (supports S0 S3 S4 S5)
[    4.316958] ACPI: Using IOAPIC for interrupt routing
[    4.327299] ACPI: EC: GPE=0x1c, ports=0x66, 0x62
[    4.327368] ACPI: PCI Root Bridge [PCI0] (0000:00)
[    4.327378] PCI: Probing PCI hardware (bus 00)
[    4.327860] PCI quirk: region 1000-107f claimed by ICH4 ACPI/GPIO/TCO
[    4.327866] PCI quirk: region 1180-11bf claimed by ICH4 GPIO
[    4.328297] PCI: Transparent bridge - 0000:00:1e.0
[    4.328376] ACPI: PCI Interrupt Routing Table [\_SB_.PCI0._PRT]
[    4.328612] ACPI: PCI Interrupt Routing Table [\_SB_.PCI0.PCI1._PRT]
[    4.332238] ACPI: PCI Interrupt Link [LNKA] (IRQs 3 4 5 6 7 9 10 *11)
[    4.332544] ACPI: PCI Interrupt Link [LNKB] (IRQs 3 4 5 6 7 9 10 *11)
[    4.332845] ACPI: PCI Interrupt Link [LNKC] (IRQs 3 4 5 6 7 9 10 *11)
[    4.333144] ACPI: PCI Interrupt Link [LNKD] (IRQs 3 4 5 6 7 9 10 *11)
[    4.333443] ACPI: PCI Interrupt Link [LNKE] (IRQs 3 4 5 6 7 9 10 *11)
[    4.333741] ACPI: PCI Interrupt Link [LNKF] (IRQs 3 4 5 6 7 9 10 *11)
[    4.334017] ACPI: PCI Interrupt Link [LNKG] (IRQs 3 4 5 6 7 9 10 11) *0, disabled.
[    4.334318] ACPI: PCI Interrupt Link [LNKH] (IRQs 3 4 5 6 7 9 10 *11)
[    4.334683] ACPI: Power Resource [PUBS] (on)
[    4.334701] Linux Plug and Play Support v0.97 (c) Adam Belay
[    4.334715] pnp: PnP ACPI init
[    4.334725] ACPI: bus type pnp registered
[    4.340188] pnp: PnP ACPI: found 10 devices
[    4.340192] ACPI: ACPI bus type pnp unregistered
[    4.340197] PnPBIOS: Disabled by ACPI PNP
[    4.340266] PCI: Using ACPI for IRQ routing
[    4.340271] PCI: If a device doesn't work, try "pci=routeirq".  If it helps, post a report
[    4.348856] NET: Registered protocol family 8
[    4.348860] NET: Registered protocol family 20
[    4.348933] pnp: 00:00: iomem range 0x0-0x9ffff could not be reserved
[    4.348938] pnp: 00:00: iomem range 0xc0000-0xc3fff could not be reserved
[    4.348943] pnp: 00:00: iomem range 0xc4000-0xc7fff could not be reserved
[    4.348948] pnp: 00:00: iomem range 0xc8000-0xcbfff has been reserved
[    4.352193] Time: tsc clocksource has been installed.
[    4.379315] PCI: Bus 3, cardbus bridge: 0000:02:00.0
[    4.379319]   IO window: 00003000-000030ff
[    4.379324]   IO window: 00003400-000034ff
[    4.379330]   PREFETCH window: f0000000-f3ffffff
[    4.379335]   MEM window: d4000000-d7ffffff
[    4.379340] PCI: Bridge: 0000:00:1e.0
[    4.379344]   IO window: 3000-7fff
[    4.379351]   MEM window: d0200000-dfffffff
[    4.379357]   PREFETCH window: f0000000-f7ffffff
[    4.379371] PCI: Setting latency timer of device 0000:00:1e.0 to 64
[    4.379390] ACPI: PCI Interrupt 0000:02:00.0[A] -> GSI 16 (level, low) -> IRQ 16
[    4.379412] NET: Registered protocol family 2
[    4.416174] IP route cache hash table entries: 32768 (order: 5, 131072 bytes)
[    4.416272] TCP established hash table entries: 131072 (order: 8, 1572864 bytes)
[    4.418578] TCP bind hash table entries: 65536 (order: 7, 524288 bytes)
[    4.419553] TCP: Hash tables configured (established 131072 bind 65536)
[    4.419558] TCP reno registered
[    4.428357] checking if image is initramfs...<6>Switched to high resolution mode on CPU 0
[    4.949654]  it is
[    5.508606] Freeing initrd memory: 7344k freed
[    5.508770] Simple Boot Flag at 0x35 set to 0x1
[    5.509103] audit: initializing netlink socket (disabled)
[    5.509122] audit(1194990306.876:1): initialized
[    5.512304] VFS: Disk quotas dquot_6.5.1
[    5.512385] Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[    5.512522] io scheduler noop registered
[    5.512526] io scheduler anticipatory registered
[    5.512529] io scheduler deadline registered
[    5.512559] io scheduler cfq registered (default)
[    5.512581] Boot video device is 0000:00:02.0
[    5.512845] isapnp: Scanning for PnP cards...
[    5.865500] isapnp: No Plug & Play device found
[    5.905960] Real Time Clock Driver v1.12ac
[    5.906094] Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled
[    5.907139] ACPI: PCI Interrupt 0000:00:1f.6[b] -> GSI 17 (level, low) -> IRQ 17
[    5.907151] ACPI: PCI interrupt for device 0000:00:1f.6 disabled
[    5.907918] RAMDISK driver initialized: 16 RAM disks of 65536K size 1024 blocksize
[    5.908220] input: Macintosh mouse button emulation as /class/input/input0
[    5.908326] PNP: PS/2 Controller [PNP0303:KBD,PNP0f13:MOU] at 0x60,0x64 irq 1,12
[    5.916556] serio: i8042 KBD port at 0x60,0x64 irq 1
[    5.916564] serio: i8042 AUX port at 0x60,0x64 irq 12
[    5.916788] mice: PS/2 mouse device common for all mice
[    5.916936] EISA: Probing bus 0 at eisa.0
[    5.916945] Cannot allocate resource for EISA slot 1
[    5.916950] Cannot allocate resource for EISA slot 2
[    5.916953] Cannot allocate resource for EISA slot 3
[    5.916957] Cannot allocate resource for EISA slot 4
[    5.916961] Cannot allocate resource for EISA slot 5
[    5.916964] Cannot allocate resource for EISA slot 6
[    5.916968] Cannot allocate resource for EISA slot 7
[    5.916974] EISA: Detected 0 cards.
[    5.917113] TCP cubic registered
[    5.917140] NET: Registered protocol family 1
[    5.917178] Using IPI No-Shortcut mode
[    5.917408]   Magic number: 15:471:803
[    5.917815] Freeing unused kernel memory: 364k freed
[    5.950645] input: AT Translated Set 2 keyboard as /class/input/input1
[    7.195734] AppArmor: AppArmor initialized<5>audit(1194990308.376:2):  type=1505 info="AppArmor initialized" pid=1186
[    7.208467] fuse init (API version 7.8)
[    7.217179] Failure registering capabilities with primary security module.
[    7.236497] ACPI: CPU0 (power states: C1[C1] C2[C2] C3[C3])
[    7.236505] ACPI: Processor [CPU] (supports 8 throttling states)
[    7.239290] ACPI: Thermal Zone [THM0] (46 C)
[    7.873469] usbcore: registered new interface driver usbfs
[    7.873508] usbcore: registered new interface driver hub
[    7.873536] usbcore: registered new device driver usb
[    7.875584] USB Universal Host Controller Interface driver v3.0
[    7.875672] ACPI: PCI Interrupt 0000:00:1d.0[A] -> GSI 16 (level, low) -> IRQ 16
[    7.875686] PCI: Setting latency timer of device 0000:00:1d.0 to 64
[    7.875692] uhci_hcd 0000:00:1d.0: UHCI Host Controller
[    7.875917] uhci_hcd 0000:00:1d.0: new USB bus registered, assigned bus number 1
[    7.875948] uhci_hcd 0000:00:1d.0: irq 16, io base 0x00001820
[    7.876122] usb usb1: configuration #1 chosen from 1 choice
[    7.876160] hub 1-0:1.0: USB hub found
[    7.876168] hub 1-0:1.0: 2 ports detected
[    7.973681] SCSI subsystem initialized
[    7.989391] ACPI: PCI Interrupt 0000:00:1d.1[b] -> GSI 19 (level, low) -> IRQ 18
[    7.989407] PCI: Setting latency timer of device 0000:00:1d.1 to 64
[    7.989413] uhci_hcd 0000:00:1d.1: UHCI Host Controller
[    7.989447] uhci_hcd 0000:00:1d.1: new USB bus registered, assigned bus number 2
[    7.989477] uhci_hcd 0000:00:1d.1: irq 18, io base 0x00001840
[    7.989639] usb usb2: configuration #1 chosen from 1 choice
[    7.989678] hub 2-0:1.0: USB hub found
[    7.989687] hub 2-0:1.0: 2 ports detected
[    7.989829] libata version 2.21 loaded.
[    8.064270] Intel(R) PRO/1000 Network Driver - version 7.3.20-k2-NAPI
[    8.064276] Copyright (c) 1999-2006 Intel Corporation.
[    8.092626] ACPI: PCI Interrupt 0000:00:1d.2[C] -> GSI 18 (level, low) -> IRQ 19
[    8.092644] PCI: Setting latency timer of device 0000:00:1d.2 to 64
[    8.092649] uhci_hcd 0000:00:1d.2: UHCI Host Controller
[    8.092683] uhci_hcd 0000:00:1d.2: new USB bus registered, assigned bus number 3
[    8.092714] uhci_hcd 0000:00:1d.2: irq 19, io base 0x00001860
[    8.092864] usb usb3: configuration #1 chosen from 1 choice
[    8.092904] hub 3-0:1.0: USB hub found
[    8.092912] hub 3-0:1.0: 2 ports detected
[    8.202567] ata_piix 0000:00:1f.1: version 2.11
[    8.202585] PCI: Enabling device 0000:00:1f.1 (0005 -> 0007)
[    8.202595] ACPI: PCI Interrupt 0000:00:1f.1[A] -> GSI 18 (level, low) -> IRQ 19
[    8.202636] PCI: Setting latency timer of device 0000:00:1f.1 to 64
[    8.202735] scsi0 : ata_piix
[    8.202790] scsi1 : ata_piix
[    8.203487] ata1: PATA max UDMA/100 cmd 0x000101f0 ctl 0x000103f6 bmdma 0x00011810 irq 14
[    8.203493] ata2: PATA max UDMA/100 cmd 0x00010170 ctl 0x00010376 bmdma 0x00011818 irq 15
[    4.848000] Marking TSC unstable due to: possible TSC halt in C2.
[    4.852000] Time: acpi_pm clocksource has been installed.
[    4.892000] ata1.00: ATA-6: HTC426030G7AT00, 00P5A0LL, max UDMA/100
[    4.892000] ata1.00: 58605120 sectors, multi 16: LBA48
[    4.908000] ata1.00: configured for UDMA/100
[    5.064000] scsi 0:0:0:0: Direct-Access     ATA      HTC426030G7AT00  00P5 PQ: 0 ANSI: 5
[    5.064000] ACPI: PCI Interrupt 0000:02:01.0[A] -> GSI 20 (level, low) -> IRQ 20
[    5.064000] ACPI: PCI Interrupt 0000:00:1d.7[D] -> GSI 23 (level, low) -> IRQ 21
[    5.064000] PCI: Setting latency timer of device 0000:00:1d.7 to 64
[    5.064000] ehci_hcd 0000:00:1d.7: EHCI Host Controller
[    5.064000] ehci_hcd 0000:00:1d.7: new USB bus registered, assigned bus number 4
[    5.064000] ehci_hcd 0000:00:1d.7: debug port 1
[    5.064000] PCI: cache line size of 32 is not supported by device 0000:00:1d.7
[    5.064000] ehci_hcd 0000:00:1d.7: irq 21, io mem 0xd0100000
[    5.068000] ehci_hcd 0000:00:1d.7: USB 2.0 started, EHCI 1.00, driver 10 Dec 2004
[    5.068000] usb usb4: configuration #1 chosen from 1 choice
[    5.068000] hub 4-0:1.0: USB hub found
[    5.068000] hub 4-0:1.0: 6 ports detected
[    5.080000] sd 0:0:0:0: [sda] 58605120 512-byte hardware sectors (30006 MB)
[    5.080000] sd 0:0:0:0: [sda] Write Protect is off
[    5.080000] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[    5.080000] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[    5.080000] sd 0:0:0:0: [sda] 58605120 512-byte hardware sectors (30006 MB)
[    5.080000] sd 0:0:0:0: [sda] Write Protect is off
[    5.080000] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[    5.080000] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[    5.080000]  sda:<6>e1000: 0000:02:01.0: e1000_probe: (PCI:33MHz:32-bit) 00:0a:e4:2a:86:b9
[    5.332000]  sda1 sda2 sda3 sda4
[    5.360000] sd 0:0:0:0: [sda] Attached SCSI disk
[    5.368000] sd 0:0:0:0: Attached scsi generic sg0 type 0
[    5.532000] e1000: eth0: e1000_probe: Intel(R) PRO/1000 Network Connection
[    5.772000] Attempting manual resume
[    5.772000] swsusp: Resume From Partition 8:3
[    5.772000] PM: Checking swsusp image.
[    5.772000] PM: Resume from disk failed.
[    5.820000] kjournald starting.  Commit interval 5 seconds
[    5.820000] EXT3-fs: mounted filesystem with ordered data mode.
[   15.400000] Clocksource tsc unstable (delta = -497273373 ns)
[   17.556000] NET: Registered protocol family 10
[   17.556000] lo: Disabled Privacy Extensions
[   17.556000] ADDRCONF(NETDEV_UP): eth0: link is not ready
[   18.216000] Linux agpgart interface v0.102 (c) Dave Jones
[   18.524000] agpgart: Detected an Intel 855GM Chipset.
[   18.524000] agpgart: Detected 8060K stolen memory.
[   18.536000] agpgart: AGP aperture is 128M @ 0xe0000000
[   18.996000] intel_rng: FWH not detected
[   19.024000] iTCO_vendor_support: vendor-support=0
[   19.024000] iTCO_wdt: Intel TCO WatchDog Timer Driver v1.01 (21-Jan-2007)
[   19.024000] iTCO_wdt: Found a ICH4-M TCO device (Version=1, TCOBASE=0x1060)
[   19.024000] iTCO_wdt: initialized. heartbeat=30 sec (nowayout=0)
[   19.216000] pci_hotplug: PCI Hot Plug PCI Core version: 0.5
[   19.248000] shpchp: Standard Hot Plug PCI Controller Driver version: 0.4
[   19.824000] input: PC Speaker as /class/input/input2
[   19.880000] IBM TrackPoint firmware: 0x0e, buttons: 3/3
[   19.892000] input: TPPS/2 IBM TrackPoint as /class/input/input3
[   19.980000] ath_hal: module license 'Proprietary' taints kernel.
[   19.980000] ath_hal: 0.9.18.0 (AR5210, AR5211, AR5212, RF5111, RF5112, RF2413, RF5413)
[   20.244000] wlan: 0.8.4.2 (0.9.3.2)
[   20.296000] ath_pci: 0.9.4.5 (0.9.3.2)
[   20.296000] ACPI: PCI Interrupt 0000:02:02.0[A] -> GSI 21 (level, low) -> IRQ 22
[   21.088000] sdhci: Secure Digital Host Controller Interface driver
[   21.088000] sdhci: Copyright(c) Pierre Ossman
[   21.128000] irda_init()
[   21.128000] NET: Registered protocol family 23
[   21.236000] ath_rate_sample: 1.2 (0.9.3.2)
[   21.244000] pnp: Device 00:09 activated.
[   21.244000] nsc_ircc_pnp_probe() : From PnP, found firbase 0x2F8 ; irq 3 ; dma 1.
[   21.244000] nsc-ircc, chip->init
[   21.244000] nsc-ircc, Found chip at base=0x164e
[   21.244000] nsc-ircc, driver loaded (Dag Brattli)
[   21.244000] IrDA: Registered device irda0
[   21.244000] nsc-ircc, Using dongle: IBM31T1100 or Temic TFDS6000/TFDS6500
[   21.276000] wifi0: 11a rates: 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
[   21.276000] wifi0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
[   21.276000] wifi0: 11g rates: 1Mbps 2Mbps 5.5Mbps 11Mbps 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
[   21.276000] wifi0: H/W encryption support: WEP AES AES_CCM TKIP
[   21.276000] wifi0: mac 5.9 phy 4.3 radio 3.6
[   21.276000] wifi0: Use hw queue 1 for WME_AC_BE traffic
[   21.276000] wifi0: Use hw queue 0 for WME_AC_BK traffic
[   21.276000] wifi0: Use hw queue 2 for WME_AC_VI traffic
[   21.276000] wifi0: Use hw queue 3 for WME_AC_VO traffic
[   21.276000] wifi0: Use hw queue 8 for CAB traffic
[   21.276000] wifi0: Use hw queue 9 for beacons
[   21.352000] wifi0: Atheros 5212: mem=0xd0200000, irq=22
[   21.356000] Yenta: CardBus bridge found at 0000:02:00.0 [1014:0555]
[   21.488000] Yenta: ISA IRQ mask 0x04b0, PCI irq 16
[   21.488000] Socket status: 30000006
[   21.488000] pcmcia: parent PCI bridge I/O window: 0x3000 - 0x7fff
[   21.488000] cs: IO port probe 0x3000-0x7fff: clean.
[   21.488000] pcmcia: parent PCI bridge Memory window: 0xd0200000 - 0xdfffffff
[   21.488000] pcmcia: parent PCI bridge Memory window: 0xf0000000 - 0xf7ffffff
[   21.488000] sdhci: SDHCI controller found at 0000:02:00.1 [1180:0822] (rev 13)
[   21.488000] ACPI: PCI Interrupt 0000:02:00.1[b] -> GSI 17 (level, low) -> IRQ 17
[   21.492000] mmc0: SDHCI at 0xd0210000 irq 17 DMA
[   21.888000] ACPI: PCI Interrupt 0000:00:1f.5[b] -> GSI 17 (level, low) -> IRQ 17
[   21.888000] PCI: Setting latency timer of device 0000:00:1f.5 to 64
[   22.124000] NET: Registered protocol family 17
[   22.136000] cs: IO port probe 0x100-0x3af: clean.
[   22.136000] cs: IO port probe 0x3e0-0x4ff: excluding 0x4d0-0x4d7
[   22.136000] cs: IO port probe 0x820-0x8ff: clean.
[   22.136000] cs: IO port probe 0xc00-0xcf7: clean.
[   22.136000] cs: IO port probe 0xa00-0xaff: clean.
[   22.816000] intel8x0_measure_ac97_clock: measured 55931 usecs
[   22.816000] intel8x0: clocking to 48000
[   24.080000] lp: driver loaded but no devices found
[   24.128000] Adding 779144k swap on /dev/sda3.  Priority:-1 extents:1 across:779144k
[   24.760000] EXT3 FS on sda2, internal journal
[   27.792000] ACPI: Battery Slot [BAT0] (battery present)
[   27.952000] input: Power Button (FF) as /class/input/input4
[   27.956000] ACPI: Power Button (FF) [PWRF]
[   28.020000] input: Lid Switch as /class/input/input5
[   28.024000] ACPI: Lid Switch [LID]
[   28.076000] input: Sleep Button (CM) as /class/input/input6
[   28.076000] ACPI: Sleep Button (CM) [SLPB]
[   28.140000] ACPI: AC Adapter [AC] (on-line)
[   28.164000] ACPI: Video Device [VID] (multi-head: yes  rom: no  post: no)
[   28.200000] ACPI: ACPI Dock Station Driver
[   28.208000] ACPI: \_SB_.PCI0.IDE0.SCND.MSTR: found ejectable bay
[   28.208000] ACPI: \_SB_.PCI0.IDE0.SCND.MSTR: Adding notify handler
[   28.208000] ACPI: Error installing bay notify handler
[   28.208000] ACPI: Bay [\_SB_.PCI0.IDE0.SCND.MSTR] Added
[   29.764000] ppdev: user-space parallel port driver
[   30.552000] audit(1194957936.546:3):  type=1503 operation="inode_permission" requested_mask="a" denied_mask="a" name="/dev/tty" pid=4582 profile="/usr/sbin/cupsd"
[   30.612000] IBM machine detected. Enabling interrupts during APM calls.
[   30.612000] apm: BIOS version 1.2 Flags 0x03 (Driver version 1.16ac)
[   30.612000] apm: overridden by ACPI.
[   30.816000] thinkpad_acpi: ThinkPad ACPI Extras v0.14
[   30.816000] thinkpad_acpi: http://ibm-acpi.sf.net/
[   30.816000] thinkpad_acpi: ThinkPad EC firmware 1UHTA6WW-1.56
[   30.824000] thinkpad_acpi: acpi_bus_get_device(bay) failed: -19
[   30.824000] thinkpad_acpi: disabling subdriver bay
[   31.000000] Failure registering capabilities with primary security module.
[   32.160000] ath0: no IPv6 routers present
[   33.700000] [drm] Initialized drm 1.1.0 20060810
[   33.740000] ACPI: PCI Interrupt 0000:00:02.0[A] -> GSI 16 (level, low) -> IRQ 16
[   33.744000] [drm] Initialized i915 1.6.0 20060119 on minor 0
[   33.744000] [drm] Initialized i915 1.6.0 20060119 on minor 1
[  145.400000] ADDRCONF(NETDEV_UP): ath0: link is not ready
[  145.488000] ADDRCONF(NETDEV_CHANGE): ath0: link becomes ready
[  170.584000] ath0: no IPv6 routers present
tn@TPA:~$

（いちいち遅くなり申し訳ありません。ありがとうございます。）

occuさん、ありがとうございます。
本日、回答していただいたのに気がつき、やってみました。

私の環境では、myautoの内容が、”ifup ath0”だけではうまくいきませんでしたが、
以下のようにしてみて、なんとか、再起動後も自動的に無線LANが使えるようになりました。

-----
#!bin/sh
ifup ath0
ifdown ath0
ifup ath0
-----

本当にありがとうございました。