Are you still having this issue? I have noticed my recordings are now corrupt due to more than one recording.
I've had this trouble recently, only affects HD channels it seems. System used ramdisk for live tv and HDD for recorded. If I'm watching and recording more than one, the HD Channel will have corruption and artefacting on playback, and even the live stream which is on a different buffering device (DDR3 ram) is broken.
Just rebuilt my server as I had to sort out the HDDs so will do a fresh install of your work and I'll have a go... but my logs where full of continuity errors.
For reference, I have 2 TBS 6981s.