Clips silent after reload - corrupted project

Hey Rui!

This is a very weird bug and a nasty one. I was editing a podcast recording. After several hours of work I rendered it and closed Qtractor. Upon editing a podcast in a sound editor, I noticed I had it amplified too much, so I went back to Qtractor, only to find the project corrupted.

Here is the project in question, a little over 100 Mb:
http://www.disc-shelf.com/var_files/

What happens is that from 55.40 clips stop playing. You can see them, they have all the waveforms, but nothing is played. If you render it - there will be silence instead of those clips.
If you copy a silent clip to another track - it starts playing. But if you try to move a clip in Track 1 or delete a clip from Track 1 (any clip, even a playing one), Qtractor freezes.
Qtractor also freezes after render.

So it seems something got broken in the clip order. Just to give you a hint, I did edit it from start to end, but then returned to the beginning and cut clips some more. But I did that before. So this is just my wild guess.

Also, if I copy the whole track 1 to some other track, seemingly random, but different set of clips will not get played. This set stays the same if you reopen the project.

Hope this helps as I had this problem before, but with a plugin (once I removed a plugin, track worked). Was surprised this time no plugin involved.