Out-Of-Sync Video

I searched for this and found nothing. We are playing a teaching video series on Tuesday nights.

The video is out of sync. It is in sync in the program on the computer screen but off on the TV where the audience is watching.

The big difference between these videos and others (which we've had no problems with) is length and size. They run about 30-40 minutes each. In fact, the file size was too big to sync and I had to load it locally only since Proclaim limits files to 600mb.

The first thing I tried was to re-encode it. Same result.

Then I shrunk the file size to get it under the 600mb. Same result.

By the way, I have played the file through the VLC media player... perfect sync on the computer and on the TV. So I believe it is something in Proclaim. 

Any thoughts or suggestions? Thank you in advace!