I have an Nvidia 8800GT (512MB) with a 23 inch LCD TV as my monitor. After using VGA for gaming etc., I switched to using a DVI cable (for the higher resolutions). Everything seemed to be ok, until I started to run games like Crysis, Gears of War and some other games: for Crysis for example, I am unable to change the resolution from the default 640x480 since the resolution selection area says the phrase 'db_VIDEOMODE'. I have also tried to manually adjust (via the config files) the resolution - without luck (I have tried this for all the problematic games), and plus, my default signal (1080i) keeps automatically changing to a 480p signal for some strange reason (when running Crysis as an example). I am having these resolution problems with some other (not all) games as well - I am either unable to change the resolution, or the maximum resolution allowed (like in Gears of War for example) would be 600xsomething.
I currently use a default desktop resolution of 1680x1050 (16:10 aspect ratio)
 
What could possibly be the solution?
 
Oh yes, and, I have tried re-installing Crysis to see if the problem would have been fixed - no luck.