I have been using a Tamron 28-200 full frame lens on my 20D. I had used the lens with a Canon film camera that I had before I bought my 20D. Until recently, it has operated flawlessly and I am satisfied with the pictures. Now I am getting an error code = 99 message when I put the lens on the camera. There is a clicking sound when I install the lens. The error code = 99 messages had increased in frequency until the present condition. The 20D manual says this error code may occur if you use a non-Canon lens and the camera or lens does not operate properly. By chance I had purchased a used Sigma zoom (for canon EOS) for my daughter and tried it on my 20D. I also received the same error message with it. My Canon 18-55 lens does not produce the error message.
Has anyone else had this type of problem?
I plan on contacting Canon, but are there other suggestions?