My PSU is a ANTEC Truepower 2.0 550w. I know this PSU is well able to handle the gtx460, but last night in my hast I wasn't looking for the second PCI cable to connect to the second slot on the card. This has to be the problem. Unfortunately im in work at the moment so I can't check if there is a second cable present, There has to be (hopefully). I'll let you know if this solves the problem. Thanks for the advice mate.