These methods have been tested under Fedora, Ubuntu and BackTrack 4. All of the following should work in almost any linux distribution to get a Belkin F5D7051 (or possibly similar device) working in Linux for WiFi access.
By default the F5D7051 conflicts with 3 drivers (the rt* set of drivers). These drivers must be disabled, rndis_wlan must be loaded and then hopefully the strange problems will go away.
1. Remove Conflicting Drivers
2. Reinsert the device
3. Load rndis_wlan
You should now restart NetworkManager and things should be good to go. You might wanna check out the bug report I made for Fedora/RH.