Can be so many things
First I would
• Trash iMovie pref file (IMPORTANT)
• Repair Permissions - Disk Util tool (IMPORTANT)
• Secure a minimum of 25Gb free space on Start-Up (Mac OS) Hard Disk
• I never use "Share to iDVD" - but "Share to Media Browser" and as Large - NOT HD or other resolutions as this too degrades the resulting DVD - it set's iMovie rendering aside and let iDVD do this - so much better
• There is a known BUG in iDVD - when done a iDVD project - do not go back to iMovie/FinalCut to make adjustments. iDVD will notice and set of the BUG - All Chapters will start as Chapter One and more.
• I only use .aiff Audio in my iMovie/FinalCut projects - all other are converted to this (44.1 kHz on Audio CDs and rest 48kHz 16-bit .aiff). ESPECIALLY audio from iTunes - I always burn as an Audio-CD .aiff (never .mp3) and then I use the files from this in my movies.
My thoughts for now. Yours Bengt W
I tried to trash the iMovie pref file. After searching around a bit, I think I found where it was supposed to be, but there were just 2 iLife files (08 and 09). I trashed those, since iMovie is part of the iLife suite. Does that sound right?
They're still in my trash if I need to pull them out, but they're: com.apple.iLife08.plist and com.apple.iLife09.plist
OK, after more web searching, I discovered how to fix the problem. This forum has several other people with the same problem, as well as, at the end, a few people who discovered how to fix it. http://www.mac-forums.com/forums/movies-video/176174-imovie-export-sound-issue-2 .html
For me, I adjusted the speed of a few clips so that they were at the preset iMovie values--100%, 50%, etc.