You can try changing the bridge interrupt settings
3Com PCMCIA Ethernet Adapter Issues
Date: 2000, Jul 26
From: David Hinds <firstname.lastname@example.org>
In /etc/sysconfig/pcmcia, try setting:
where NN is 0x00, 0x01, 0x02, 0x03, 0x80, 0x81, 0x82, or 0x83. One of
those may help. It is an obscure fix but I don't have a better one.
to: "You can try changing the bridge interrupt settings"