Movies no longer play in iTunes or ATV

Yes, they play fine in all other applications I have, including PS3 streaming via PS3 Media Server (good ole' reliable).

Since iTunes won't allow a reset to a previous version, I'm now considering uninstall and re-install my older version. I'm always hesitant to do this because I recall there being major issues when re-importing my library (9,000+ songs and ~300 movies). If I remember correctly, my genre's are always messed up and album art didn't necessarily save properly, despite how long it took me to get it the way I like. Maybe I'm just not backing up the necessary files correctly when doing a re-install.

Well, in case anyone is reading this and willing to offer ideas, I did uninstall iTunes 11.1.5.5 and re-installed the last full version I had saved 11.1.1.11 (not really sure of the last version I was on before everything stopped working). Nothing was lost during the re-install (all libraries, playlists and such are still as they were....I was expecting this not to be the case). However, this process didn't change the video playback problem. I'm at a loss of what this could be. I went through the audio issues mentioned on another thread and did the recommendations, with no change. I did manage to find a few videos that still do play. The only difference I could see is that they are listed as "low complexity" and in stereo. I suppose it probably is an audio thing, though I have no idea why it's an issue now, when it never has been in the past. Please help. Thank you.

Okay, for those that might have had the same problem as me, I have resolved it. I simply unplugged the Apple TV's power supply, waited a few mins, plugged it back in and all worked just as it did before. I think I was more lost on the issue because they wouldn't play in iTunes, which they still don't. I never played them in iTunes before, but was constantly testing it out since I thought it was part of my problem (and easier to test instead of running back and forth to the TV after each mod I tried to troubleshoot). I could care less if they don't play in iTunes, as long as streaming to ATV works, and it does. Not sure what threw a wrench in this whole scenario, but a hard power reset did the trick.