Transcode only plays first 30sec

Hello everybody,
the Server (0.6.2 b7) is working on an QNAP 259+ NAS. AVI files are playing just fine.
When playing mkv files with transcoding only the first 30 - 90seconds of the movie plays fine. After that time the TV jumps right to the next file. Then again ~one minute is playing > skipping to next file
Someone an idea what could be wrong with the serviio installation? Also removed it, and reinstalled it ... no change
Also "chmodded" the /tmp/Serviio folder to 777, also no change.
The tmp file is growing to ~66723840 byte, and then i can see it's skipping to new file and the the tmp file beginns to grow again
Anybody with same expirience?
the Server (0.6.2 b7) is working on an QNAP 259+ NAS. AVI files are playing just fine.
When playing mkv files with transcoding only the first 30 - 90seconds of the movie plays fine. After that time the TV jumps right to the next file. Then again ~one minute is playing > skipping to next file

Someone an idea what could be wrong with the serviio installation? Also removed it, and reinstalled it ... no change

Also "chmodded" the /tmp/Serviio folder to 777, also no change.
The tmp file is growing to ~66723840 byte, and then i can see it's skipping to new file and the the tmp file beginns to grow again

Anybody with same expirience?