Media player "playback error" on mkv files?

Hi.

I have aTV flash 1.1 installed, but when i try to play some mkv files i get this “playback error”. Its only on some mkv files so can anyone tell me what is wrong?

Or if anyone have the same problem?

Can you try updating to version 1.2 to see if the issue persists?

Sadly after updating it still doesnt work. 

Its strange because some mkv files (about 5gb) can play while others with the same size cant… Dunno if there is some special codec but would be strange…