Hi,
here is my solution that works for me:
1) Run TeamViewer on HTPC computer
2) Connect to it from another PC
3) Disconnect all video card outputs (default monitor changed to Generic Non-PnP Monitor)
4) Change resolution for Generic Non-PnP Monitor to same that you use on primary output
5) Connect video card outputs
6) Try to turn off and turn on your primary monitor
Regards,
vladab_2000
Now it seems to work for me. Important is that you really unplug the TV to be able to change the general VGA resolution.