I took the camera out for a spin yesterday, it was just above freezing but the batteries (in non-OEM battery grip) seemed to be doing fine. The camera started making funny noises like it was trying to focus even though it wasn't up to my eye (eye focus was on) and then things got stranger...

The only function of the camera that work are the mode selections, Av, Tv etc. and selecting shutter or aperture via the wheel. AF is toast. Selecting anything else (custom functions, metering mode etc) also toast. And the strangest thing is that you can hear the lens stopping up/down when you change the aperture. You can also select an aperture and take the lens off and it will be stopped down. It's almost like it got permanently stuck in the Depth of Field Preview mode. The DOF preview button doesn't seem to work either. Any advice?