gp500store.co.uk

Hello chaps,
I recently purchased GP500, but have been having quite serious graphical issues with it, basically the framerate halves after one lap, and then the game will fast forward after a couple more laps, sending me into the gravel.
I tried to register on the website www.gp500store.co.uk several times, but it fails to send the confirmation emails out.
So I was wondering, would it be possible for a member there to lend me their login details, just for a day or two, so I can see if there is a cure for the problem in the forum, which is unfortunately closed to non members?
I would be extremely grateful if anyone could help me out with this.

Thanks in anticipation,

Salvatore