Screen flashes on and off when conneted via dvi.?

brand new video card an ati 1650 pro. i had a similar issue with my old video card i dont think the card is the issue. i connect the monitor using dvi. somtimes i get a blank screen. ather times it flashes on and off. the machine also will not boot somtimes wile using dvi. after the bios screen it resets as if you were pressing the reset on over and over agin. no problems with vga. i find the computer reseting very strange. and i hate the fact im unable to use dvi. my drivers are all up to date aswell. anybody have any ideas?????