Ah nice you've fixed my problem....
I did a post with this same problem, i installed on my second boot XP (instead of vista which had this problem) and it worked fine but then i started having this problem with XP, I just installed the latest ATI drivers as well.
Now to rollback my drivers and get it working again
I'll probably be able to rollback my drivers on Vista and get it working on that OS again
Nobody's Perfect and i'm Nobody