I don't want to bring up any false hopes, but I've tried to get ndiswrapper working with WPA2 on 3 different wireless devices, all without any success. I've tried all different configurations but none ever worked.
First solution (not a really good one...):
I could make connection when i changed the wifi security options to 'WEP' or either 'no password'. Try both and see if you can connect in those situations. If you can't, it's your configuration; if you can, it means ndiswrapper can't handle WPA2-AES (as I have experienced)... I know this really isn't a solution since you effectively decrease (WEP) or disable (no password) your security, but this is more a diagnostic tool
Second solution... Do you have any other possibilities? What chipset does your wireless device have? If it's an atheros chipset, you could go for the madwifi driver (given you have a pci wireless device and not an USB one)...
Third solution: try other drivers with ndiswrapper! Sometimes you can have huge differences between XP and Vista drivers... Or even using drivers of other ('closely-related') devices, alltho this is more trial-and-error.
fedora can be quite b*tchy when it comes to wifi, I'm afraid
I gave up and switched to wired LAN :P
P.S. this seemed quite stupid to me at first, but i can never be too sure; you did install the wpa_supplicant package before trying to connect, right? This package handles wpa(2) encrypted connections