HD TV & mp4 Strange Prob

I have a full HD TV.
TV Model - Samsung LED TV UN40EH5050FXZA

Strange prob with mp4 movies
Every mp4 movies stops at 2 hours 12 mins 14 secs playing & returns to menu.
No probs with any other format.

Movies are on USB & USB can be attached to the TV.
I tried with 2 GB & 32 GB USB but the same prob.

I tried 3 mp4 & 3 mkv movies of 2 hours 30 mins.
mkv movies worked fine.
Alll 3 mp4 movies stopped & returned back to the menu. All the mp4 movies stops at 2 hours 12 mins 14 secs. If I remux these mp4 movies with mkvtoolnix then the movies are changed from mp4 to mkv & plays fine.
What could be the prob?
Any info/solution?

Probably a bug in the firmware of your tv. See if there is a firmware update and if your problem is listed in the fixes.