Canon T2i mov > Cineform > MainConcept mp4 > MP4 Faststart

I shot a video of a band performing in the park. Final output on PC: perfect sync. Uploaded to my website: video slightly behind.

After much research and trial & error, I found this listing dealing mostly with YT issues, but the last comment from bibbetyboo (thanks!) did the trick: "make sure you don't save project markers in your render. "

http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=713280

Removing that check mark made sync correct. Go figure...