Sound and video out of synch in DVD final

Hi, Y'all-
My iMovie project is long but within iDVD limits. No errors on the burn. However, even though everything plays fine in iMovie (and in all iDVD previews), the resulting DVD that gets burned has the audio and video out of synch.

I'm on a twin G5 (older, not Intel) and have tried restarting computer, iDVD, and made several burns. Tried deleting the first transition from titles into the initial audio/video. All no luck. BTW, I imported all the movies into iMovie directly from my camera initially. Ideas? Thanks!

-Ranger