I'm having intermittent problems with a small number of clips using audio for a show. The odd clip is either refusing to play or is seizing shortly after cueing. However, it's not all the time (it's been about 4/5 shows out of a eight week tour so far). Initially my workaround was to seperate the audio completely onto a 16x16 pixel black squares which have then used as a master layer to keep the video in sync, but I'm still having the odd same problem (I've just seen it myself during a rehearsal).
All the clips are rendered using ProRes proxy codec with audio set to 16-bit little Endian, 48.000khz.
I'm running Catalyst m466B on OS10.9.5 on a Mac Pro 5.1, both QuickTime x and 7 are installed. I also reformatted the ssd trying to sort it out. Audio is output via a motu 828. Video is being sent to a datapath x4 set to 2048x1536 @ 50htz. Framerate of catalyst is locked to Screen 2 div 2 (which it says is 24.99Hz).

I'm guessing there's an issue with QuickTime but I'm running out of solutions.

Clearing all the layers seems to fix the issue for the rest of the show.

Any thoughts would be appreciated.

Barret