Odd glitch with HDTV for Monitor GTX 670

I use my 42-inch Toshiba TV (http://www.newegg.com/Product/Product.aspx?Item=N82E168...) as a monitor for my computer (it's hooked up through an EVGA NVIDA GeForce GTX 670) using an HDMI cable at 1920x1080 (1080p) with the "Enable desktop resizing" checked and set to auto, and the desktop resize mode reported to display set to "Do not report". It looks great...

However, I have a very weird glitch that happens sometimes (a half dozen times during a two-hour period). The screen will scrunch up into about a two-inch vertical space in the middle of the screen. It looks like the whole image of what should be there is on the screen, but it's just squeezed into a tiny sliver. It then pops back after a half second to a second to the normal full resolution. This happens not only in games, but also when I'm just browsing (non-graphically intense activities). Every so often it will do a vertical one too, with the whole image squashed down to a horizontal bar centered on the screen. I can't figure out any sort of rhyme or reason to why it happens, or the frequency. Sometimes they happen fairly close together (several times spaced a few seconds apart). Other times it just happens once. It seems quite random. I have done some Google searches, but can't seem to find anyone else who has had this problem. Does anyone have an idea of how to troubleshoot this?

Yes, I have restarted my computer.
Yes, my graphic card drivers are up-to-date.
No, my graphics card is not overheating (32 c)