You could try this: click here
I assume this is the one you have and it may be worth trying the latest drivers. My own experience with these sort of adapters hasn't been great though !
Funnily enough I bought a Netgear DG834GT with the 108mb version of the USB adapter you have last week and I'm sending it all back to Ebuyer today for a refund (RMA)and will get a 'wired' router next time.
Apart from other woes (with the router)I found that when the adapter works it is OK (although the max. connection I get on Super G was 72mbs), but it is unreliable in dropping the wireless connection and often requires a reboot of the router to reinstate . It also gets damn hot being USB2....
Sorry that I have nothing else useful to add.
Good luck !