I picked up a 20" mirror iMac last night. It's great, except Photo Booth asks for me to plug in a camera or close another app using the iSight. I don't have the mirror widget installed. Tried resetting SMC, PRAM, software update, repairing permissions, logging in as a new user. It doesn't show up in Profiler under any USB bus. Basically, I tried everything short of reinstalling OS X, which doesn't seem like it'll help. Hardware problem? Should I be able to get the iMac replaced? I don't want to let the Genius Bar take it from me--they manhandled my Macbook last time I left it.