I found one video that causes mediapalyer 1.1.1 to restart randomly. No memory warning message, nothing. It will just be playing and then it restarts. I have couchsurfer, weather and media player installed. No other 3rd party extensions. ATV 4.3 OS as well, untethered jailbreak.
The movie in question is Incendies with english subtitles. Sometimes the subtitles won’t play either, I have modified the subtitles options to increase the font size to +3 and colour to Yellow.
The format of the movie is
Xvid MPEG-4 Video
frame rate 23.976023
Audio is A52 Audio (aka AC3)
if you are looking for the file to test this is the name
the subtitles file is