A few hours ago, I created a short training video (around 3 minutes in length) on iMovie '08 (7.1) using video imported from a Sony DCR-TRV10 Handycam. Satisfied with the work I did so far, I quit iMovie to take my dinner. I didn't export/save the video to another format since I wasn't done yet. When I went back to iMovie after a few hours, I couldn't get iMovie run; it immediately crashed after launching. Eventually, after about a dozen attempts, I was able to get iMovie to run without crashing, but only for about 10 minutes. In that span of time, I noticed that many thumbnail clips in the Library and Project panes were grey boxes. I was able to play the training video I created, but the portions corresponding to the greyed thumbnails had no audio. I tried exporting the Project, but iMovie crashed as it was about to complete the process. Later, I was able to determine there was nothing wrong with the software itself since I was able to successfully launch it using another account. So, I trashed the iMovie Projects and iMovie Events folders. iMovie launched without crashing. What could I be done wrong? Tomorrow, I'll re-import the video from the Handycam and see if the same problem develops.