If you installed the native drivers plus ndiswrapper, that would probably lead to a conflict.
Try some manual troubleshooting; as root, in a terminal:
modprobe -r ndiswrapper
modprobe -r rt2800usb
modprobe rt2870sta
VLwifi
Dont work...
root:# VLwifi
cat: /etc/wifi-radar/wifi-radar.conf: No such file or directory
cp: cannot stat `/etc/wifi-radar/wifi-radar.conf': No such file or directory
2010-07-22 09:18:40: ERROR: Could not find Intel PRO/Wireless 3945ABG Network Connection
Invalid parameter 1: -.
Then vlwifi ask me that i want to use xp drivers in ndiswrapper...cancel...no wireless cards found..