I would definitely be changing that power supply. ATRIX is not a high-quality brand - for example, compare the specs on these two Silverstone units with the specs of your unit:
560W;
500W; (specifically the amps per +12V rail). My personal preference in brand is Silverstone, but you can find excellent recommendations in that power supply thread I linked to above. I would get a 650W at least - higher if you plan to upgrade your system at all in the near future. As they say, it's better to have it and not need it than need it and not have it...