i dont trust ocuk testers, had a borked mobo from them which wouldnt post the comp if u changed nething in the bios, had to reset bios to get comp to post...consequently couldnt set cd drive to boot from and then couldnt install windows...rma'd it and was sent it straight back (only took 2 weeks)...
(finally fixed that one by forcing the comp to crash during a bios flash and auto reload a default bios it had saved when it does that, got it all working to find out the onboard audio I was hoping to use in that comp was not working either, could not be bothered with yet another very poor rma which probably wouldnt happen so I just wacked in a cheapy 5.1 sound card)
similar problem (took 6 weeks in total) with a 6800gt which artifacted and only finally got money back when it completely failed and fan wouldnt even spin any more/comp detected no gfx card
tbh you have the right to demand your money back
if not who is the card made by? most manufacturers have atleast a years warranty, some lifetime, just send it back to one of them or atleast get in touch with them
tbh I think the rma policies of most online computer shops are pretty shoddy, the online/telephone/mail order company I work for, all our customers have to do is ring up, tell us the item doesnt work within a year (sometimes more) and we'll arrange for someone to take a van out the next day, pick it up and deliver a new one, we'll deliver a new one before we get the old one back as well if they want it later.
having to pay usually registered post to send back something you bought from a company which doesnt work is a complete rip off and a royal waste of money and I think its very poor customer service, im not just saying ocuk are bad for it but a lot of companies that sell computer hardware, there deffinately needs to be a better system.
especially when it comes to down to 1 component that there is a known issue with (7900gtx....so many of them are failing) and you whole comp is broken and your just wasted £300-400+ and are then having to pay to get something sorted out which is not your fault....not good