Last week, I decided to take the plunge and flip my 5D Mark II cameras with 5D Mark III bodies. The other thing I had been drooling over was the Canon 70 – 200mm f2.8 L II IS lens, so added that to my shopping cart. Today, after shooting less than 100 images on my 5D Mark III, I was stopped in my tracks by an Error 70 message. It persisted even though I changed lenses – the error message was still displayed with both the 24-105mm F4 L Series IS USM and the brand new 70-200. The forums suggest that this is a problem with the CF card, but I formatted this card in the 5D Mark III prior to shooting anything. Since I had this problem with the 5D Mark II, and Canon ended up replacing the motherboard, I’m not convinced that this is simply a write problem with the CF card. Right now, the plan is to exchange the camera for a new body. We shall see… I’ll keep you updated.