Possible Pro Tools OMF Bug?

Today I received several OMF 2.0 files from the picture department with embedded audio. Under certain circumstances, the timecode of the Pro Tools session generated from the OMF was incorrect so all the material was out of sync.

I’m not sure what version of software is being used on the Avid, but the movie was shot with 3-perf film. Since this throws off all the footage counters, we are cutting in timecode. OMF 2.0 files were generated for me but with all the media, they were going to be larger than 2 GB. To remedy this, the assistant split each reel in half, usually around the 10 minute mark, and sent me OMFs for each reel.

I opened each OMF in Pro Tools 6.4.1 with the built-in DigiTranslator. After conversion, I immediately changed the timecode from 24 frame to 29.97 pulldown. This is what I always to with OMFs. However, I found that the second OMF, the one that would start somewhere around 10 minutes into the reel, would always be out of sync. Sometimes only 1 frame early but in a few instances, up to 6 frames early. The first OMF for each reel, the one that started evenly on the hour, was always in sync.

After much trial and error, I found that if I left both OMFs in 24 frame timecode. Combined them, and then changed to the combined session to 29.97 pulldown, everything stayed in sync. For some reason, if an OMF doesn’t start at an evenly on the hour of timecode like 01:00:00:00 or 02:00:00:00 and you attempt to change the timecode in Pro Tools without first resetting the start time of the session to an even hour and maintaining timecode, then the session will fall out of sync. It’s possible that the version of Avid software and the fact that it was a 3-perf film might also have something to do with this. I haven’t had a chance to experiment more.