I have both CS5 and CS6, running on a mac with OSX 10.6.8 a 2.3 Ghz i7 processor and 8 Gig RAM I'm getting the same result in both CS5 and CS6, I'm trying to export an edit that was shot on a Canon 7D. When I choose "match sequence settings" the resulting file is the correct lenght but has no audio or video. It's completely blank. Any ideas?
You could try different export settings.
Don't use Match Sequence Settings. Take manual control over your exports, make sure you have the correct settings.