Video on HDTV stopped working

My Home entertainment rig plays DVD, movies from hard drive, WoW and some family pictures. It worked fine for a year, but now will not show the desktop from a cold boot or restart. This is very repeatable.

1) hooked up another monitor, got XP Pro all set. Powered off, plugged in Sony 50 inch LCD projector TV. Powered on and set up Sony as primary monitor. Sony suggested resolution is same as 1080p but the DRM stuff makes that a mess. I set up for 720P and everything works. Changed TV to primary monitor. ATI Catalyst setting up a 9400 on an Asus A8n-SLI Deluxe (single video card). Rebooted to check and all is well.
2) turn off and cold boot. No video after Windows starts to load on either screen. Reboot to safe mode, no video; Enable VGA mode, no video.
3) booted up Win7 CD as I wanted to install it anyway. Install went as expected, all drivers found. TV and monitor working. Played movies at 720P, changed TV to primary monitor, surfed the net. All seems good, reboot and no video when Windows loads. Tried VGA mode and Safe mode again, no video.
4) rinse and repeat with XP
5) rinse and repeat with 7

any ideas what changed? It seems Windows is detecting the Sony's 1080p preferred settings and trying to use it instead of what I told Windows to use. I say this because the Sony has come up with some DVI/DRM warnings on reboot - but that is not consistent.