I take it you've checked this page out?
Ubuntu - WifiDocs/WirelessCardsSupported
Something I found that helped me immensely setting up Ubuntu Dapper with WPA.
Ubuntu Dapper WPA
If you can't get your card working, I highly recommend the PCMCIA Netgear WG511T. It worked 'out of the box' for me, and I have recently done a mod to mine to add an external antenna.
Good luck.