Problem with Belkin wireless USB adapter

I just bought a XPS 710 (Vista Ultimate) PC which did not have a wireless adapter built in as standard so I chose the Belkin Wireless USB adapter from the options menu.

When I opened the box of the adapter there was a note saying that it was not certified for Vista and that drivers were available from the manufacturer's website. I downloaded these (they are beta drivers) and all seemed to work well for a few hours until after a reboot it no longer detected any wireless networks. It also seems that it is not automatically recognised by the device manager - I have to disconnect/reconnect it after every reboot. Even if it shows up in the device manager as working fine it won't display any wireless networks to choose from.

 

Can anyone help?