
I was using my 50D at the weekend and after a few shots I couldn't change the aperture setting - it came up with a 00 value and wouldn't change. I tried changing modes (Tv, P etc) but the aperture remained on 00. I did all the usual stuff like turning it on and off and taking out the battery, but it didn't help.
When I got home it worked ok for a while, and then the same thing happened.
Any ideas ?