Solution to iMovie 6.0.3 consistent crashes

For a while now, my copy of iMovie HD has been crashing when I try to open it. I've been putting off finding the solution since I haven't needed to do much with iMovie, but today I needed it.

I first reinstalled the iMovie 6.0.3 update. No luck. Then reinstalled QuickTime 7.2. Still crashing. An examination of ~/Library/Logs/CrashReporter/iMovie HD.crash.log showed this thread as the culprit:

Thread 5 Crashed:
0   com.apple.CoreFoundation       	0x90811125 CFRetain + 56
1   com.apple.MediaBrowser         	0x67e01f56 -[MediaGrabberiTunes _loadMusicThreaded] + 733
2   com.apple.Foundation           	0x927f52e0 forkThreadForFunction + 123
3   libSystem.B.dylib              	0x90024227 _pthread_body + 84

That led me to a thread on iPhoto crashes on Apple's discussion forum, with solution posted by Terence Devlin: start up GarageBand.

I started up GarageBand, quit it, and now iMovie HD is working fine. Although Terence recommended saving something from GarageBand, I found that just starting the application was enough. Apparently something in GB's initialization routine fixes the problem.