On 8/8/05, Marc Durocher <md underscore lasalle at yahoo dot ca> wrote:
> 
> Aug 8 18:43:40  /kernel: dc0: watchdog timeout
> Aug 8 20:23:21  /kernel: dc0: watchdog timeout
> Aug 8 20:23:21  /kernel: dc0: TX underrun --
> increasing TX threshold
> Aug 8 20:51:38  /kernel: dc0: watchdog timeout
> Aug 8 20:53:40  /kernel: IP firewall unloaded
> Aug 8 21:04:10  /kernel: dc0: watchdog timeout
> 


From the dc(4) man page:
--
watchdog timeout
A packet was queued for transmission and a trans-
     mit command was issued, but the device failed to acknowledge the trans-
     mission before a timeout expired.  This can happen if the device is
     unable to deliver interrupts for some reason, of if there is a problem
     with the network connection (cable or network equipment) that results in
     a loss of link.  
--

I'd first make sure if you have a plug and play OS option in your
BIOS, it's set to no, then try switching the card into another PCI
slot, if that doesn't work try switching cabling and hub/switch port,
and if that doesn't work, replace the NIC.

-Chris