I have the Canon 10D. I'm at 8000+ photos and I've been having problems for the past couple of months where the camera goes into sleep mode excessively and too quickly (it's set to sleep after 2 minutes) and can take a long time to "wake up" from it. This isn't the usual standby after no use. I thought it was an incompatibility with my Sigma lens at first (I had a similar problem w/ one when I first got the camera a few years ago and had to send it to Sigma for repair), but now it's happening w/ my Canon 24-105 L lens as well.
Has anyone heard of this? Any thoughts about it?