Canon 7D H.264 files are 2 frames out of sync after import on FCP 7.03 and Avid 5.5

I've run into the strangest issue with some H.264 Quicktimes shot on the 7D. The footage plays down in sync prior to import, but when I import to FCP or Avid, each clip is two frames out of sync. Here's what troubleshooting I've done so far, none of which resolved the issue:

FCP:
Transcoded via MPEG Streamclip to 422, import
Log and capture H.264 files, transcode, import
Import H.264 directly (I know, it's a delivery and not an editing codec)

AVID:
Link via AMA
Link via AMA, then transcode to DHxHD 115
Import using DNxHD 115
Transcode 7D files to DNxHD 115 via MPEG Streamclip, import

But here's the kicker. When I export a clip, it's back in sync again. So it's only out of sync after it's been ingested.

I'm using FCP 7.0.3 and Avid 5.5 on an early 2011 MacBook Pro, i7, 8GB RAM, all media imported via external Firewire,

If anyone has any insight into this odd behavior, by all means let me know! I'm stumped.

"Started on a Steenbeck, but wouldn't go back."