It was everything OK. But… I have updated “world” and found out some problems with Kdenlive. All tracks are playing without sound. And after export project to the video-file, this one has no sound too. Kdenlite was not changed and now version is 0.9.2. So the problem obviously into related libraries. The first possible library of course is ffmpeg (1.2.6). I tried to downgrade this one to the 1.0.8 version… and…It is COOL!)) Sound is ok ) So the problem is relations between kdenlive and ffmpeg-1.2.6. This post is for everybody who maybe will find out such problem.