Working with material from 2 5D mark II cameras, and one 7D camera, as well as material from an iPhone 4. The timeline settings are visually:
1920 x 960 (custom 2:1 widescreen crop)
no upper/lower setting
23.98 frame rate
audio 48.00 khz
timeline problem: exporting to quicktime the file loses audio synch at a certain point about 6.5 minutes into the 55 minute file. It then becomes more significantly out of synch as the file plays to the end by several seconds. I have mixed down the audio to one " .aif " file at 48.00 khz (the audio rate was recorded at 23.96...
I have tried deleting some early iPhone 4 footage from the timeline to see if that has affected it due to different frame rate or other settings.