Oops, forgot to post details of my problems with the 3Com drivers as well. Make sure the power settings are set all the way up all the time. I found that one out the hard way as well.

I use the configurator program to change my network name on the Airport before hooking up the PCMCIA card.

Make sure to request the encryption driver CD off the 3Com web site. It includes new drivers, new firmware, and support for encryption. The airport encryption key needs to be converted to hex with a 0x added in front of it to then put into the 3Com encryption driver settings for encryption to work.