Same here, but with a slight variant.

* Hardware
 - Gigabyte GA-EX58-UD3R (rev. 1.6), CPU: Core i7 - 920, RAM: 3x Corsair TR3X6G1600C9
 - Onboard ethernet controller: Realtek 8111C

08:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03)
    Subsystem: Giga-byte Technology Device e000
    Flags: bus master, fast devsel, latency 0, IRQ 2294
    I/O ports at 7e00 [size=256]
    Memory at fd6ff000 (64-bit, prefetchable) [size=4K]
    Memory at fd6f8000 (64-bit, prefetchable) [size=16K]
    [virtual] Expansion ROM at fd600000 [disabled] [size=128K]
    Capabilities: <access denied>
    Kernel driver in use: r8169
    Kernel modules: r8169


Settings for eth0:
    Supported ports: [ TP ]
    Supported link modes:   10baseT/Half 10baseT/Full 
                            100baseT/Half 100baseT/Full 
                            1000baseT/Full 
    Supports auto-negotiation: Yes
    Advertised link modes:  10baseT/Half 10baseT/Full 
                            100baseT/Half 100baseT/Full 
                            1000baseT/Full 
    Advertised auto-negotiation: Yes
    Speed: 1000Mb/s
    Duplex: Full
    Port: Twisted Pair
    PHYAD: 0
    Transceiver: internal
    Auto-negotiation: on
    Supports Wake-on: pumbg
    Wake-on: g
    Current message level: 0x00000033 (51)
    Link detected: yes

Connected to a Zyxel gigabit switch.


* OS
 - Ubuntu Jaunty 9.04


* Scenario 1:
 - Linux mtt-r3 2.6.28-3-rt #12-Ubuntu SMP PREEMPT RT Fri Apr 17 10:09:11 UTC 2009 i686 GNU/Linux
 - Stock r8169 driver

I got a crash pretty soon (over 6 retries, I had a mean time of 3 to 8 minutes, even with small amount of transfers), with the following log report:

Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982385] ------------[ cut here ]------------
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982387] WARNING: at /build/buildd/linux-rt-2.6.28/net/sched/sch_generic.c:227 dev_
watchdog+0x211/0x220()
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982389] NETDEV WATCHDOG: eth0 (r8169): transmit timed out
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982390] Modules linked in: binfmt_misc ppdev bridge stp bnep video output input_po
lldev lp parport snd_hda_intel snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi raw1
394 snd_seq_midi_event video1394 snd_seq snd_timer snd_seq_device psmouse serio_raw pcspkr iTCO_wdt iTCO_vendor_support 
snd soundcore joydev snd_page_alloc nvidia(P) agpgart hid_cherry usbhid ohci1394 ieee1394 r8169 mii fbcon tileblit font 
bitblit softcursor
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982412] Pid: 85, comm: sirq-timer/6 Tainted: P        W  2.6.28-3-rt #12-Ubuntu
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982414] Call Trace:
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982418]  [<c013bde0>] warn_slowpath+0x60/0x80
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982421]  [<c02cde95>] ? __next_cpu+0x15/0x30
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982423]  [<c0131c9d>] ? find_busiest_group+0x15d/0x7f0
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982426]  [<c0129967>] ? enqueue_task+0x57/0x70
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982428]  [<c02d309d>] ? strlcpy+0x1d/0x60
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982431]  [<c043b4c2>] ? netdev_drivername+0x32/0x40
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982433]  [<c0450431>] dev_watchdog+0x211/0x220
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982435]  [<c0102da7>] ? __switch_to+0xb7/0x1a0
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982438]  [<c0511ed8>] ? _spin_unlock_irq+0x8/0x40Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982440]  [<c0130850>] ? finish_task_switch+0x50/0x120
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982443]  [<c0146b31>] run_timer_softirq+0x181/0x380Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982445]  [<c0450220>] ? dev_watchdog+0x0/0x220
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982447]  [<c0450220>] ? dev_watchdog+0x0/0x220
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982448]  [<c0141b6b>] ksoftirqd+0x12b/0x260
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982450]  [<c0141a40>] ? ksoftirqd+0x0/0x260
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982452]  [<c015164c>] kthread+0x3c/0x70
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982454]  [<c0151610>] ? kthread+0x0/0x70
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982457]  [<c0105547>] kernel_thread_helper+0x7/0x10
Jul  2 16:37:01 mtt-r3 kernel: [ 8685.982458] ---[ end trace cd96ab8c933e2dd5 ]---
Jul  2 16:37:35 mtt-r3 NetworkManager: <info>  (eth0): device state change: 8 -> 3 
Jul  2 16:37:35 mtt-r3 NetworkManager: <info>  (eth0): deactivating device (reason: 0). 

The workstation hangs: unresponsive keyboard, frozen windows but cursor can be moved.


* Scenario 2:
 - Linux mtt-r3 2.6.28-3-rt #12-Ubuntu SMP PREEMPT RT Fri Apr 17 10:09:11 UTC 2009 i686 GNU/Linux
 - Realtek r8168 driver, from package r8168-8.012.00.tar.bz2

Same as above.


* Scenario 3:
 - Linux mtt-r3 2.6.28-13-generic #45-Ubuntu SMP Tue Jun 30 19:49:51 UTC 2009 i686 GNU/Linux
 - Stock r8169 driver

After 1 hour of sustained transfers I couldn't manage to make it crash.