Did you repair the disk or repair permissions for the disk (your last post is a little vague). In disk utility, after selecting the hard disk there are four buttons; Verify Disk Permissions, Repair Disk Permissions, Verify Disk and Repair Disk. Make sure you click Repair Disk Permissions. Failing that try creating a new user and seeing if the problem still occurs with that user. If it does, you may have to reinstall iMovie.