blackbox@openface.ca said:
> I can't seem to figure out how to track down the cause of this
> problem, or how to get rid of it. 

Did you succeed in increasing the receive ring?
What about the interrupt sharing? Can you try
to rearrange things so that the card gets an own
interrupt (I know it's a PC...), or at least give
some data points?
Does it happen on all 3com cards on on one only?

> When it does happen, everything freezes for about
> 5 seconds preceeding the message (I guess thats the Ethernet card
> reinitializing?)

Strange that this takes so long. Perhaps the hardware
hangs up completely.

> Maybe I should just switch to other cards?  Which cards are easily available
> and known to be good?  I've heard good things about the fxp/EtherExpress Pro
> cards.

I can't give a serious advice, but I'm using boards
with the Intel chip in 6 or 8 boxes and didn't have
problems so far. The DEC/Tulip chips are potentially
better (a bit faster and well documented), but the
'143 is not well supported by NetBSD, and clone chips
seem to be of varying quality, su you'd have to watch
out what you buy.
But as I said, I don't have problems with 3c90xb cards
either, even in data acquisition applications.

best regards
Matthias