Aug 11 16:05:39 alarmpi kernel: [178378.440089] smsc95xx 1-1.1:1.0: eth0: unregister 'smsc95xx' usb-bcm2708_usb-1.1, smsc95xx USB 2.0 Ethernet
Aug 11 16:05:39 alarmpi dhcpcd[265]: eth0: carrier lost
Aug 11 16:05:39 alarmpi systemd[1]: Stopping Automatic wired network connection using netctl profiles...
Aug 11 16:05:40 alarmpi ifplugd[121]: Link beat lost.
Aug 11 16:05:40 alarmpi ifplugd[121]: Executing '/etc/ifplugd/netctl.action eth0 down'.
Aug 11 16:05:40 alarmpi dhcpcd[265]: received SIGTERM, stopping
Aug 11 16:05:40 alarmpi dhcpcd[265]: eth0: removing interface
... etc ...
Meh - even standard Arch has the problem, so maybe it still is a hardware issue ...
uname -a
Linux alarmpi 3.6.11-11-ARCH+ #1 PREEMPT Tue May 14 16:12:58 UTC 2013 armv6l GNU/Linux
Odd though coz that's: archlinux-hf-2013-06-06.zip