Blue Screen

[Philadelphia]

I have 2 5870's, one with 2mb and the other 1mb. When I have the 2mb one in I've been getting the dreaded blue screen. I took it out and put in the 1mb and I'm not getting the blue screen.

Is the card the issue? Could it be the power supply? Could it be the driver? Could it be.....????

Thanks for your thoughts.

EDIT: So much for the 1mg not getting the blue screen, it just got it too