I have narrowed my Com port problems down to two possible culprits.

The first is some kind of a line ringing problem.  That one won't go
away if that is it.

The second is that the wd0 driver is somehow 'stealing' or masking the
interrupt for the com port.  This is my most likely culprit, because it
is definitely a problem on the client (my system) end.  I sat in the ISP
frame room and watched the modem in action.  The modem at that end tries
to send info to this end.  The modem at this end blythely ignores it.
The nexty thing the modem at that end sees, it is disconnected and the
next modem in the pool is called into service.  Note that on the ISP
end, there isn't the redial sequence that is apparent at this end.  

I am willing to try the 'unsupported' com driver to see if it fixes this
problem; all I need is that address...

-- 
Dave Burgess  (The man of a thousand E-Mail addresses)
*bsd FAQ Maintainer / SysAdmin for the NetBSD system in my spare bedroom
"Just because something is stupid doesn't mean there isn't someone that 
doesn't want to do it...."