Most likely your primary monitor has the video driver set to a refresh rate other than 60hz. I'd check that out.
Here are the timings for HDTV all at 60hz refresh rate:
480p and 960i is 31.5 Khz horizontal scanrate
540p and 1080i is 33.75 Khz horizontal scanrate
720p and 1440i is 45 Khz horizontal scanrate
If your monitor driver sets the refresh to 75hz, for example, the monitor would need to respond to these timings:
480p and 960i would be 39.375 Khz horizontal scanrate
540p and 1080i would be 42.187 Khz horizontal scanrate
720p and 1440i is 56.25 Khz horizontal scanrate
Since most HDTVs will only operate in a horizontal scan rate range of 31-34 Khz, (fixed pixel type TVs can go to 46Khz) the 75hz refresh causes this range to be exceeded. Computer monitors will operate in much, much wider ranges than HDTVs. Consult your manual for acceptable signal. You should be able to force your video to 60hz refresh rate.
Last edited by rbinck; 03-29-2005 at 11:17 AM..