I leave my HTPC on all of the time. I use my HTPC as a server too so I dont have it set to sleep at any point in time. The TV that is connected to the HTPC is a 46" Samsung LCD TV that has a 16:9 aspect ratio, which I have configured in windows and it works perfetly as expected. I usually leave Media Center up all of the time becuase this HTPC is a dedicated HTPC box. When I'm not using the HTPC I shut off the TV but leave the HTPC on.
The problem is that when I turn the TV back on the picture aspect ratio is switched to the "square" 4:3 aspect ratio. I have to then break out a mouse, close MediaCenter and then re open it to get the correct 16:9 aspect ratio back again.
Any way to fix this?