Right, I forgot about the mirror foam. It's a thin strip that runs on the top of the film chamber, and the mirror will flip up when you press the shutter to take your pic, then flip back down. If it's really sticky, scrape it off. You don't need to replace it right away, but I have had some EM's that had sticky foam and the mirror would actually stick in the up position and wouldn't want to come down. Make sure you have fresh batteries in the camera, or you will have issues w/ the mirror sticking in the up position too.