bought a canon 7d used a few weeks ago, shot about 1000 shots with it and I got err 30 a couple times today. I hit it into my hand in frustration, quite hard, and everything seems to be working again (for now anyway). The images came out black indicating to me that the shutter remained closed rather then opening? The camera has only done 8k shots, and the warranty expires, today.. thoughs? edit: oh, its in mint condition otherwise.