I have tried a 450 Geforce but the PC only seems to reset when put under heavy load. So the 450 was fine, I don't have another GPU to test with and Wootware only have the Galax cards on hand. I have left it in Wootware's hands since I bought everything from them so they should be able to find the issue.
I am just going to report progress and my experience with this RMA here. If nothing else guys can get an idea of what to expect with RMA-ing with a supplier.
ok what make was that corsair psu's. I think the 12v rail might not be enough.
Sorry for not understanding correctly. So you say the geforce 450 is fine but under load it restarts?