I take my previous comment back. This occurs with a clean install on a Shuttle SK22V10 with 9.10.

Here my latest messages log:

Nov 15 16:37:07 cube kernel: [338855.220066] usb 4-1: USB disconnect, address 2
Nov 15 16:37:07 cube kernel: [338855.220246] gspca: disconnect complete
Nov 15 16:59:35 cube kernel: [340203.511700] usb 1-2: USB disconnect, address 2
Nov 15 17:22:10 cube kernel: [341558.673739] eth0: link down
Nov 15 17:22:23 cube kernel: [341572.047070] eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
Nov 15 18:40:07 cube kernel: [346235.989022] ------------[ cut here ]------------
Nov 15 18:40:07 cube kernel: [346235.989044] WARNING: at /build/buildd/linux-2.6.31/net/sched/sch_generic.c:246 dev_watchdog+0x1f6/0x210()
Nov 15 18:40:07 cube kernel: [346235.989051] Hardware name: SK22V10
Nov 15 18:40:07 cube kernel: [346235.989056] NETDEV WATCHDOG: eth0 (via-rhine): transmit queue 0 timed out
Nov 15 18:40:07 cube kernel: [346235.989061] Modules linked in: nls_iso8859_1 nls_cp437 vfat fat isofs udf crc_itu_t binfmt_misc ppdev snd_via82xx gameport snd_ac97_codec ac97_bus snd_pcm_oss snd_usb_audio snd_mixer_oss snd_usb_lib snd_seq_dummy snd_pcm snd_page_alloc snd_mpu401_uart snd_seq_oss snd_seq_midi snd_seq_midi_event snd_seq snd_rawmidi snd_timer snd_seq_device iptable_filter snd_hwdep ip_tables snd nvidia(P) soundcore x_tables gspca_stv06xx i2c_viapro psmouse k8temp shpchp serio_raw gspca_zc3xx gspca_main videodev v4l1_compat lp parport usb_storage via_rhine mii ohci1394 ieee1394 sata_via amd64_agp agpgart
Nov 15 18:40:07 cube kernel: [346235.989154] Pid: 0, comm: swapper Tainted: P           2.6.31-14-generic #48-Ubuntu
Nov 15 18:40:07 cube kernel: [346235.989159] Call Trace:
Nov 15 18:40:07 cube kernel: [346235.989173]  [<c014518d>] warn_slowpath_common+0x6d/0xa0
Nov 15 18:40:07 cube kernel: [346235.989183]  [<c04b07c6>] ? dev_watchdog+0x1f6/0x210
Nov 15 18:40:07 cube kernel: [346235.989191]  [<c04b07c6>] ? dev_watchdog+0x1f6/0x210
Nov 15 18:40:07 cube kernel: [346235.989199]  [<c0145206>] warn_slowpath_fmt+0x26/0x30
Nov 15 18:40:07 cube kernel: [346235.989208]  [<c04b07c6>] dev_watchdog+0x1f6/0x210
Nov 15 18:40:07 cube kernel: [346235.989218]  [<c0127c38>] ? default_spin_lock_flags+0x8/0x10
Nov 15 18:40:07 cube kernel: [346235.989227]  [<c05707da>] ? _spin_lock_irqsave+0x2a/0x40
Nov 15 18:40:07 cube kernel: [346235.989237]  [<c030719b>] ? blk_rq_timed_out_timer+0x10b/0x120
Nov 15 18:40:07 cube kernel: [346235.989245]  [<c01501b7>] run_timer_softirq+0x117/0x200
Nov 15 18:40:07 cube kernel: [346235.989256]  [<c016a125>] ? tick_dev_program_event+0x45/0xe0
Nov 15 18:40:07 cube kernel: [346235.989265]  [<c04b05d0>] ? dev_watchdog+0x0/0x210
Nov 15 18:40:07 cube kernel: [346235.989274]  [<c014b3b0>] __do_softirq+0x90/0x1a0
Nov 15 18:40:07 cube kernel: [346235.989283]  [<c015ff63>] ? hrtimer_interrupt+0x183/0x210
Nov 15 18:40:07 cube kernel: [346235.989291]  [<c014b4fd>] do_softirq+0x3d/0x40
Nov 15 18:40:07 cube kernel: [346235.989298]  [<c014b63d>] irq_exit+0x5d/0x70
Nov 15 18:40:07 cube kernel: [346235.989306]  [<c011dcf7>] smp_apic_timer_interrupt+0x57/0x90
Nov 15 18:40:07 cube kernel: [346235.989314]  [<c0103d71>] apic_timer_interrupt+0x31/0x40
Nov 15 18:40:07 cube kernel: [346235.989322]  [<c0126fc5>] ? native_safe_halt+0x5/0x10
Nov 15 18:40:07 cube kernel: [346235.989329]  [<c010a486>] default_idle+0x46/0xd0
Nov 15 18:40:07 cube kernel: [346235.989335]  [<c010a55d>] c1e_idle+0x4d/0x100
Nov 15 18:40:07 cube kernel: [346235.989342]  [<c010202c>] cpu_idle+0x8c/0xd0
Nov 15 18:40:07 cube kernel: [346235.989352]  [<c056c096>] start_secondary+0xc6/0xc8
Nov 15 18:40:07 cube kernel: [346235.989358] ---[ end trace 3f7b77e45b14cefa ]---
Nov 15 18:40:07 cube kernel: [346235.989506] eth0: Transmit timed out, status 0003, PHY status 786d, resetting...
Nov 15 18:40:07 cube kernel: [346235.990210] eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
Nov 15 18:40:25 cube kernel: [346253.989164] eth0: Transmit timed out, status 0003, PHY status 786d, resetting...
Nov 15 18:40:25 cube kernel: [346253.989870] eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
Nov 15 18:40:41 cube kernel: [346269.989164] eth0: Transmit timed out, status 0003, PHY status 786d, resetting...
Nov 15 18:40:41 cube kernel: [346269.989876] eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
Nov 15 18:40:59 cube kernel: [346287.989197] eth0: Transmit timed out, status 0003, PHY status 786d, resetting...
Nov 15 18:40:59 cube kernel: [346287.989892] eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
Nov 15 18:41:13 cube kernel: [346301.989169] eth0: Transmit timed out, status 0003, PHY status 786d, resetting...
Nov 15 18:41:13 cube kernel: [346301.989917] eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
Nov 15 18:41:25 cube kernel: [346313.988171] eth0: Transmit timed out, status 0003, PHY status 786d, resetting...
Nov 15 18:41:25 cube kernel: [346313.988867] eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
Nov 15 18:41:43 cube kernel: [346331.988466] eth0: Transmit timed out, status 0003, PHY status 786d, resetting...
Nov 15 18:41:43 cube kernel: [346331.989161] eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
Nov 15 18:41:59 cube kernel: [346347.988862] eth0: Transmit timed out, status 0003, PHY status 786d, resetting...
 .
 . etc, etc. Now my ethernet is mute. Does not respond to anything.
 .

Seems to occur after applying a fair amount of traffic (tried copying large files using FTP and SMB).

I am considering going back to 9.04 as rebooting everytime I transfer large files is getting annoying.

Thanks for your attention.