While trying to take a picture today, it failed to work. It said "busy" in the viewfinder and then froze. I turned it off and back on and it was still frozen and this time the viewfinder info wouldn't show. I took the battery grip off and put a battery in the camera. Same problem. I put the grip back on and it sprung back to life. Should I worry? Anyone else have these problems? I should add, it's only 4 months old and has probably less than 1500 actuations.