I have a media PC running media portal hooked up to my HDTV via HDMI. The TV is a couple of years old now, so only supports 1080i, which is 1920x1080@25Hz. I've got it connected to my PC via a HDMI compatible AV receiver.

If I power up the amp (wait for it to boot fully) followed by the TV| and finally the PC, all is well and I get a picture. If I deviate from that sequence, or don't wait for the amp to power up fully, or even switch the amp to another video input (for example, my PS3). The PC sees this and defaults the screen resolution/refresh rate to 1920x1080@60Hz. So, I end up with a blank screen.

To fix this I have to use UltraVNC from a PC and change the refresh rate back to 25Hz.

So, is there a way to turn off that auto detection, or to manually define what resolution/refresh rates the monitor can do.

I'm using the on-board Radeon 3200 video and do not have any of the AMD software installed as it seems to cause problems with video playback. So, I'm looking for a native vista fix, or possible some 3rd party software.