Brought the above mentioned card to put in a new rigg for a mate and it keeps locking up in games. phoned up ocuk and i was asked me what psu i was using. When a informed them it was a hyper type R 580, i was told it only had a 20amp 12v rail, which is insufficient to run a x1900xt. Is this true? I have also tried the card with ny enemax liberty 500, which has a 22amp 12v rail and it made no difference.