There are some servers on Ubuntu Server 10.04 with that particular hardware: output of hwinfo.
The problem is the hangup when machine experiences a traffic higher than 10Mb/sec for several minutes; only hardware reset can bring the machine back to life.
Before the hangup occures, dmesg displays a repeated message like that:
[106142.897269] r8169 0000:03:00.0: eth0: link up
[106142.897280] NOHZ: local_softirq_pending 08
[106146.198770] r8169 0000:03:00.0: eth0: link up
[106146.198782] NOHZ: local_softirq_pending 08
[106146.537895] r8169 0000:03:00.0: eth0: link up
[106146.537907] NOHZ: local_softirq_pending 08
[106147.525354] r8169 0000:03:00.0: eth0: link up
[106147.525365] NOHZ: local_softirq_pending 08
But, of course, the PHY is always connected.
Are there any known ways how to fix it?