I have several old Aironet PC4800 PCMCIA adaptor cards. These cards work fine in the unencrypted mode but they seem totally unable to connect with WEP encryption enabled. I have tried them with various 2wire and Linksys routers. I have tried them on a Mac Powerbook with OS9. I have tried them on windows 95 and XP machines. I have updated their firmware. I have no trouble using WEP encryption using my Linksys WPC11 cards. I read on the net that the PC4800 cards cannot encrypt at data rates higher then 2MB, so I have tried them at 1 and 2MB and they still do not work. I have read that the PC4800B fixes the data rate problem with encryption. I cannot find anything in the materials on this site which says that the PC4800 should not work with WEP. Does anybody know anything about this issue?