[Cin] Cutting mkv causes video to stop at cut points

[Igor BEGHETTO]

@ Andrea_paz
Thanks! I downloaded "test1.mkv" from 
https://github.com/ietf-wg-cellar/matroska-test-files and it seems to 
work good in Cinelerra-GG.

@Stefan
Thanks for your info file and good 
"sample_1280x720_surfing_with_audio.mkv" file works for you too. Yes, it 
might help to see your mkv file to test it on other distros. Can you 
share that file privately or publicly? (Sorry, my reply, tomorrow, I hope)

IgorBeg