Help, iMovie has quit working. It just freezes when opened.

I put my many projects in a different folder because iMovie 11 was freezing and I couldn't accomplish anything. I put 1 project in at a time and it worked great for 5-6 projects. Then I wanted to combine 5 projects into one. To do that I found if I put the 5 projects in iPhoto I could then find them in the event library window and drag them to the project area, edit the volume and export to iTunes as one movie. However, now putting one project in the project folder results in nothing but a frozen iMovie I have to force quit. Oh yea, you have to close iMovie and reopen it to get the new project to show up or at least that worked for awhile. I trashed the preference for iLife and cleaned up premissions. Any other ideas to get the thing to work and loose the spinning ball....?