Fix bugs preventing sample accurate recording to HDCAM

Where I work, we laydown audio tracks to HDCAMSR tape from one ProTools HD system and simultaneously catch stems on a 2nd chasing ProTools HD system and the edits are consistently off by a different amount every time. Usually it's a least 4 frames and some variable amount of samples between 0 and 1500 and the offset is different every single layoff even when no offsets change. This has been happening since before we moved to PT 8. It usually takes 3-4 layoff attempts with different offsets to land an accurate layoff within 100 samples, but we should be able to find some setting that consistently delivers sample-accurate layoffs to HDCAM.
We've had experts in to validate our Sync, tried multiple HDCAM decks that work perfectly with our AVIDs, and tried using Serial Time-Code and LTC, with no improvement. This is super annoying.