Black Screen w/ Sound SLI GTX 260

I have a system with 2 gtx 260 216 core pny graphics cards. I can play any game in windowed mode fine. All of my games now start in windowed mode by default. When i press alt+enter to force fullscreen, the screen goes black and all i hear is audio. I can only exit the black screen if i unplug and replug the dvi cable from my card. I can still play games in fullscreen by unplugging and replugging but this is a huge hassle i never had to deal with before. Any ideas?

Thanks in advance

-Autiep03