serial ports under 2.0.x

[Gerry Swetsky]

Sounds as if you're experiencing an interrupt conflict on your serial
port.  Similiar thing happened at vpnet.  Check /etc/conf/cf.d/asy.  If
another device is using either interrupt three or four there is a way
to open only ONE of the two serial ports and thus free up the interrupt
in conflict.

I'd write more, but I gotta get to work.  Mail me for more info.