I have a PB Ti G4 (Model: M8592LL/A) with the original Airport card. I cant get this to connect to WPA networks. WEP wireless works fine. When I have a network set as WPA the PowerBook sees the network and when I attempt to join it recognizes it as a "WPA Personal" network, however I cannot join the network at all. Is there anything I can do for this? Do I have to buy an Airport Extreme card??