Lock Screen Resolution?

I have my mini hooked up via HDMI to my Samsung TV. I leave the Mac powered on all the time (it never sleeps), and everytime I turn off the TV, the Mac changes it's resolution back to something rediculous like 520x680 or something. Is there any way to lock the resolution so that it stay at 1080p no matter what happens? If I need to hook it up to a smaller monitor I'dd manually change it before I move it. This problem makes it impossible to leave the HTPC software running full time becuase I have to continually change the resolution. Kind of negates the entire reason I bought the Mini...convenience.

Let me know if you have any ideas. Thanks in advance.