I used my new Canon 20D on a wedding shoot yesterday. In the middle of my shoot I turned it on to use it and the camera was not responding to the shutter button (I was in AF mode). I turned it off then on to "reboot" it and the camera would not turn off! To my dismay I had to open the battery door in order for it to turn off.
It aslo didn't recognize that I had a CF card in it when it was on.
Anyone run into problems like this????