Belkin N150 (Ralink 2870 chipset) not working

On my previous couple of Hacks, I've used a Belkin and Belkin N adaptor, running roughly the same set up each time, with slightly different hardware. They usually run perfectly by installing the Ralkink 2870 chipset and modifying the kexts my the Product and Vendor ID.

This time though, I have installed Snow Leopard on a hard drive using the same method as usual but for some reason, it won't work.
I've had my Belkin N running on Leopard on the HD I'm currently using but can't get the N150 to run on Snow Leopard on it.

This has been going on for about a week now and no matter what I try, I can't fix it and it's obviously driving me nuts. If anyone can help, I'd be so so grateful.

Here's what I've learnt from my week with it:

-System Profiler will recognise the card to the point where it can even say what mA is needed to power it.

-The Ralink Wireless utility will open up but will always read "no device". When the device is in, it will change to "disconnected" and shut down.

-I had it working briefly in safe mode but it stopped working after I downloaded a couple of updates (java updates etc, no system updates)

-I installed the Airport-like app that Jardran had created and Aqua Mac had mod'd for RT2870 and it can see my wireless network and get 100% signal but it still doesn't let me connect to the internet.

Colin