Sync drift across reels

[Pete Gates]

Hi,
I've just been posed a problem to solve. Scenario is this:

24 Frame 35mm - > Telecined frame for frame at 25fps
Avid Media Composer film mode at 25fps
All production audio in Avid.
Time line audio exported as OMFI 2 to dialogue editor.
25fps PAL Quick Time video (with guide track) exported to dialogue editor.
At premix tracks are in phase with guide from PAL Beta at end there is a 1 frame error. It seems to drift linearly across the duration of every reel, there is no 'kick'. The 1 frame error is predictable and on every reel, they're getting it by playing from top to tail or by playing at the top then shuttling down - out both times.
As far as I can tell, everything is clocking/locked correctly in the theatre (2 Pro-Tools, Nuendo, Akai DD8s and DFC).
I Haven't been told whether the error is the same direction each time (they think it is) and whether it's the picture or the sound that's longer.

I don't have every last bit of information yet but any ideas?

Thanks,
Pete

[DigiTechSupt]

Did you compare the telecine vs. the original to see if there might have been a 1 frame error during that process?

If it's the same every time, I'd start at the beginning (the telecine) and verify that it's correct.