If SSID broadcast is disabled many cards will do that. So enable SSID broadcast and try it with WPA security.
Remember I don't have your manual so you have to convert my instructions to match your router.
I have a microsoft 802.11b wireless network in my home. Windows XP home ed. secvice pack 2. HP desktop AMD Athlon 64 connected directly to the router. I also have an HP laptop Win. XP SP2. in another room. When the network is put into the "secured network" mode on the host desktop computer, the laptop in the other room requires that a passcode be entered before the laptop can get on my wireless network. We enter the required passcode, the laptop goes onto the secured network no problem.
I have a second laptop Dell Pentium III, win. XP SP2 DLink Air DWL 650 that getonto the wireless network perfectly when the network is in the unsecured mode.
When network is in secured mode, this laptop indicates that I am connected. When I go to Int. Explorer, I am actually not connected. I cannot get the computer to come up with the screen that requires me to enter the passcode. I try to disconnect and reconnect, and it never puts up the "enter passcode' screen, and I'm not connected to the network. I get a message, cannot find server. Very strong signal from router. Any thoughts? Thanks, Pete M.