It's nice to finally arrive at the thread addressing my exact situation; imovie09 has an apparant WIDE SPREAD problem w/ the audio sync. My mac only narrowly escaped destruction in a violent and brutal manner over this issue. I was considering throwing it in the street and running over it w/ my car so it would fit in the lawn mower.
I have a 15 min project created for my son's 4th grade CA Mission project. It includes 100+ individual clips, MANY WITH SLIGHT SPEED ADJUSTMENTS. (102-103%). About 10 min into the BURNED/EXPORTED project, the audio sync gets wacky (audio is late, clips are mute, etc). BUT my project has speed adjustments THROUGHOUT - right from the beginning, & the problems don't start until 2/3 of the way thru, so the sync problem can't be tied ONLY to the speed adjustments. I have created 5 other imovie 09 projects, ALL w/ similar speed adjustments, & this is the 1st problem exporting.
And, as this thread title states, the problem is ONLY on export/burn/share. THE PROJECT PLAYS FINE IN iMOVIE09.
I tried many things: exporting via Quicktime, saving the project in High, Medium, throwing away imovie plist files, clearing cache, running no other processes during burning, even buying 4 GB of new RAM for my macbook. Nothing helped.
Then, I found this thread and focused on the ADJUSTED SPEED of my clips. I went back and adjusted the speed of the clips FROM THE POINT OF THE PROBLEM FORWARD back to 100%, leaving the first 8 or 9 minutes alone (which includes many clips adjusted to 102, 105, even one at 800%). Since that part of my movie was fine after burning, I left it alone.
It finally worked. It had taken several HOURS of research and of course $75 in memory to try to fix it, but it's finally perfect. Here's what I think:
There must be a limit to the amount of speed adjustments you can make in an imovie09 project. Either in size or duration. Here's why I think this:
1) Many of us are finding these sync problems (after burning) towards the end of our projects, when we've applied similar speed modifications to the entire project. Why is that?
2) I've made several other imovie09 projects with exactly the same type of changes to the clips (speed, volume, ducking, separating audio, adding different audio from another file, muting, smoothing, etc) and I have not run into this problem - but the one thing that is different is the length and amount of the clips I've adjusted. The project that gave me the problem is the one w/ the most amount of speed changes...and of course the problem didn't come until the last few min of the project.
It's possible that those people who have only applied one speed change and had the problem immediately after that point may have applied the change to a large or long clip, using up the limit in that one clip. I may be wrong here, I'm no expert, but it does seem coincidental that so many of us are finding this problem ONLY TOWARDS THE END OF OUR PROJECTS.
Anyway, my problem is fixed, I left my speed adjustments alone for the first 2/3 of my movie, and the last 1/3 is all at 100%. It burned fine and plays on my tv great. What a huge PAIN this whole thing was though. Had I known, I would've created the movie on my pc using movie maker. The only positive thing apple did for this problem was host this forum for us to figure it out ourselves. So, thanks to everyone who has taken the time to post here!