2 Net work cards 2 locations one problem...

I have a Linkless wireless "g" card and a network card
which is part of my mother board. I use the Wirelss Card
set up when I'm at home and when I go to my freinds house I
use the motherboard network connection for his lan. When at
Home I disable the mother board one and at my friends house
vise versa so as not to cause any funky conflicts.

The problem is at my freinds house my connection keeps
droping and I get a cable not pluged in error message about
an hour after setting it all up. The only thing that seems
to restore it is to uninstall and re-install TCPIP.

Also no other computers drop from the network but mine. We
are all running win 2k.

Any Ideas on how to prevent my network connection from
going down like this? Also is there anyway to set up a
network workgroup ID specific to the card I'm using? I have
to keep changing it when I go to his house , or when I'm at
home.

Any help would be much appreciated