I just received a refurbished GD235HZ from cheetahdeals.com and everything seemed to be doing fine. I plugged my xbox 360 into the monitor to test it out via hdmi cable since my computer has not been built yet.
I played Black Ops for a while on it with no problems. I decided to throw a DVD into my xbox and after you click on "play dvd" the screen goes black and the dvd never shows on the monitor and the dvd title menu never appears. What sucks more is that I can't seem to back out of this black screen. I have to turn the xbox off and then the xbox dashboard will reappear.
I also tried to watch netflix through my xbox. I picked an HD movie out and after the movie finished loading, black screen again....just like with the DVD disc that I tried to use.