I installed the latest version and everything seemed to be great - could see regular (iTunes) content okay but opening Nito or XBMC would create a restart. Tried unplugging and it temporarily worked. Then, I could get the XBMC and Boxee to work, but moving to my iTunes content at the menu level would crash my aTV. After a restart, same thing. Later I tried to view a movie from my iTunes sync'd library and it caused constant restarting without any playback. Resorted to full factory reset and then everything from the stock aTV perspective worked the way it was supposed to.
I tried searching through the help but wasn't able to easily find similar issues...any tips would be great, as I am a little hesitant to try reinstalling again, as I don't want to waste my TV watching time constantly restarting and resetting the aTV....