A Canon systems user of 20 plus years, I purchased an EOS 20D # 1320920547 on 08/05.05 from BH on 9th Ave. in NYC. Within 1-2 months of the purchase I encountered the error 99 message on a few ocassions – and each time removing and reloading the battery resolved the problem. Now after nearly a year of normal (and very careful) operation I suddenly (literally from one day to the next) notice that I cannot shoot on the program setting of my EOS 20D using the wide end of my 17-85 IS lens without getting briefly straying and failing autofocus and an error99 message and, no image after taking the shot! This phenomenon appears to be accompanied by a partial loss of control over the aperture and an overall failure of accurate metering. I can however shoot at the mid or tele end of the same lens with normal results. And when I set the camera to completely manual mode I can shoot normally. What could the explanation for this be and how best can this be permanently resolved, repaired and prevented?