Are you experiencing unexplained iDVD crashes when clicking on Burn ? Are you using iDVD 4.0.1 and OS X 10.3.7 ? Have you tried removing DivX QT components to no avail ?

Well, all of the above applied to me with a DVD with motion menus and slideshows (no movie files at all) and it happened on two separate Macs (with the same OS/App loads) but appears to have been cured by re-installing iDVD from the iLife ’04 DVD and then running the iDVD 4.0.1 updater.

The clue to this (for me) was that simply running the iDVD 4.0.1 updater caused the installer to bomb out saying that iDVD wasn’t installed under /Applications, when the Finder said that it was. I’m not sure what caused the upset, and I use iDVD that rarely that I may have gone through more than one OS point update and never used it, but the fix is relatively painless – hope it can help someone else.