Importing Stills - iMovie 4

I am nearly done with a graduation movie, but suddenly I'm having trouble importing stills through iphoto. When I select the picture through the photos tab, it looks fine, until I drag it to the timeline. Then it becomes mostly a black still with just a tiny part of the original photo showing. I did recently repair & verify permissions on the hard drive, but other than that, I can't think of anything I've changed. Can you tell me what to try next?