I just recently purchased Plural Eyes 3 and I'm having issues with the timeline being exported back into FCP7. I synched my video and audio up in Plural Eyes and it plays fine in the Plural Eyes window. However, when I export the timeline back into FCP 7, the audio and video are in synch for the first couple of minutes but then it goes out of sync.
I'm shooting with a 5D Mark III and h4n. The issue seems to occur when the clip is about to be broken in half and by that I mean when you record a long clip and after you stop recording, the camera says file will be divided into multiple 4GB files.
Well, I have a 7 minute interview which has been split into 3 files and the audio is off by just a few frames.
Check that audio frame rate is the same in the timeline, raw footage, and sequence settings. Almost always this turns out to be a case of the slight difference in rates which explains why it starts out in synch but then drifts away.