AC3 Audio is cut off at the beginning

Feb 7, 2014 at 10:42 PM
Edited Feb 7, 2014 at 10:42 PM
Hi
I'm trying to split an mkv wich AC3 audio into several parts. For example:
Part 1 - Frames 0 to 5918
Part 2 - Frames 5919 to 7146

The video looks fine but the audio seems wrongly cutted, the audio of Part 1 is now longer than the video and in part 2, the first half of a second is without audio.
I tried Passthru and encoding, nothing helped.
Can anyone help?
Thank you