I have got my new 50D from Jessops. I own a 40D too. I love 50D but I got dreaded err99 after 250 shots. I am sure it is not the battery, CF card and unlikely be due to Lens too. It happened when I was tracking a flock of flying pigeons with it. I had a 70-200 4L IS attached, and was using AI Focus mode. Only tracking but not shooting. As I was running out of the memory I had it for JPEG saving mode!!!
Walked into Jessops store at Oxford street. And then reinserted the battery to keep it going again. Its only one week old. I have never got this with my 40D.
Should I return it? FM 1.0.2

