Thanks for the "told you so" remarks, but that doesn't solve or try to solve the problem. The reason I only took the DS3 was because like I said, it was an oversight, and second, I had only planned to do landscape and other object oriented photography. The model thing was a "heard through the grapevine" deal that would have paid for my trip.
It didn't reflect badly on me as a professional simply because I explained why I didn't have a back up and why I really didn't want to bring one. They almost didn't get me to do it anyway because I DIDN'T want to do people this time out. And since I was shooting landscape, I didn't want to shoot with the 5D. I wanted and needed the extra pixels--which I don't often need when doing people. I figured if something goes wrong with the 1DS3 then I'll turn around and save the money until it's fixed. But I never thought a camera this young and expensive would pull something like this. Perhaps a failed main board, but this problem is all over the net.
Regardless of mechanical breakdowns which do occur, really, should their be a contact problem ERR 01 with so many people out there, or a focus screen problem, or ERR 99? I mean this is a camera that is unrivaled in both price and photographic standing. It's a Mercedes Benz, not a Kia.
Yes, I did clean the contacts on the body and the lens. First time I used a rag and some rubbing. Today I figured I didn't have anything to lose except time and money, since if it needs Canon repair, it's going in anyway--so I cleaned it with a firm pencil eraser. Yeah I know, thin coating of gold gets rubbed off using this technique originally used to clean soldered circuit boards from oxidization. Yadda yadda. I also removed the battery. It's not locking up, meaning will not shoot at all. I can simply turn the camera off and the shutter comes back down and I can shoot again. What happens is that a dead giveaway that it's going to error is that it won't auto focus--because there is a communications problem. However, sometimes it WILL auto focus, release the shutter, and then error.
After using the pencil eraser, I shot 20 shots with the 24-70 and had no problems, but I'll bet dollars to donuts, it's an internal situation and it'll be back. In any event, even if I don't get a repeat up to the time I call Canon, it will be going back to Canon after I get home if Canon support thinks it needs to.
Micheal: Yes, thought of that, but it's on all three lenses leading to the conclusion that it's the camera. But I did clean the contacts on the lenses too. It almost looks like the springs behind the contact pins on the camera are not strong enough to stay out far enough, or they get sticky and can't punch out far enough. It could be a part defect in that respect. That's why perhaps why I read that people who have this problem have no other problems after sending the body into Canon for repair. Who knows. Thanks for responding.