"em0: watchdog timeout" after move from 7-PreRelease to 7-RELENG

[Jeffrey Goldberg]

I just updated to 7-RELENG using csup and compiling from source a  
machine that had been happily running with a Intel PRO/1000 GigE card  
on 7-PRERELEASE

Building went fine, but as soon as I booted multiuser, I had my  
network connection go up and down like a Yo-Yo.  Here is an excerpt:

Mar  7 16:34:40 kreacher em0: link state changed to UP
Mar  7 16:34:40 kreacher em0: link state changed to UP
Mar  7 16:37:52 kreacher em0: watchdog timeout -- resetting
Mar  7 16:37:52 kreacher em0: link state changed to DOWN
Mar  7 16:37:52 kreacher em0: link state changed to DOWN
Mar  7 16:37:56 kreacher em0: link state changed to UP
Mar  7 16:37:56 kreacher em0: link state changed to UP
Mar  7 16:38:08 kreacher em0: watchdog timeout -- resetting
Mar  7 16:38:08 kreacher em0: link state changed to DOWN
Mar  7 16:38:08 kreacher em0: link state changed to DOWN
Mar  7 16:38:12 kreacher em0: link state changed to UP
Mar  7 16:38:12 kreacher em0: link state changed to UP
Mar  7 16:38:22 kreacher em0: watchdog timeout -- resetting
Mar  7 16:38:22 kreacher em0: link state changed to DOWN
Mar  7 16:38:22 kreacher em0: link state changed to DOWN
Mar  7 16:38:26 kreacher em0: link state changed to UP
Mar  7 16:38:26 kreacher em0: link state changed to UP
Mar  7 16:38:33 kreacher em0: watchdog timeout -- resetting
Mar  7 16:38:33 kreacher em0: link state changed to DOWN


There was nothing else stressing the system at the time.  The load  
average was around 0.25 on a dual core system.  Everything works fine  
if I use the on-board nfe ethernet port on the machine, but I would  
like to get Gigabit ether back working on this machine.

I don't really know what sorts of information I need to be looking at  
or reporting.  Any advice would be welcome.  The only change on the  
system for many weeks has just been my move to 7-RELENG today which  
appears to have triggered the problem.

Cheers,

-j