Belkin USB F5D7050 causes panic

I am working on a friend's G4 PowerMac with Leopard. I have been trying to set up a USB wireless adapter F5D7050. I downloaded the Ralink drivers, installed them, plugged in the adapter, found it in the Network prefs and activated it, but as soon as I try to access my router, I get total kernel panic followed by the grey curtain over the screen forcing a shutdown.

Now if I do a restart with the device plugged in, the mac panics on startup at the final windows as it is setting networking up.

Any ideas of things I can try? BTW, I set the same adapter up on my intel macbook with the same drivers and it worked fine (Snow Leopard).

Thanks; Rick