If you are experiencing the problem,

1. Open your project in iMovie.
2. Insert a DV or Ken Burns still clip at the beginning of your project as a placeholder.
3. Delete the affected still clip.
4. Reimport the photo used for the still clip.
5. Reapply any transitions or effects to the reimported still image if needed.
6. When finished editing, delete the clip added in step 2.

To prevent this from occurring with new projects insert a DV clip or Ken Burns still image as the first clip of your project. (In other words, apply the Ken Bruns Effect to a "still" black frame, maing it a "moving" clip.)

Another serious glitch --
I have found that iMovie (unlike Final Cut Pro & Final Cut Express) is "brought to its knees" when trying to display complex editing jobs. My guess is it has something to do with the way iMovie uses the Mac's processor. I've experienced this in three Projects (or "segments" of) films. (I'm running a Dual 1 GHz, G4 PPC with 1 MB L3 cache per processor and 768 MB DDR SDRAM.) Anyway, what happens is the project just starts "stuttering" badly during playback within iMovie. Jeff Carlson discusses this in his "iMovie DH . . . for OSX" book on page 64 and offers some suggestions for improvement. His solutions don't work for me.

What I do is back up a few steps, put up with the stuttering, then export ("Share") what I've done so far as a Full Quality QT. I then open a new Project and Import the QT as a "clip."

MORE HERE

Problems with FileVault and iMovie:
READ THIS

This document will be updated as more information becomes available.