I was out shooting some harvesters working in the paddocks yesterday and had taken about 8 shots when the camera (7D) froze and the aperture blades stayed closed, I went back to the car and found I had an error 01 message on the screen telling me to clean the lens contacts. I did this with a pencil eraser then refitted the lens took about 4 more shots and up pops the message again. I fitted my 150-500 and finished the shots I wanted and returned home to be out of the worst dust. I tried cleaning the contacts again to no avail. I tried the lens on my 400D and immediately got an error 99 message; I tried all my other lenses on both cameras with no problems. I also changed batteries twice.
It looks like the 18-250 Sigma has died after only about 35000+ shots :-). I emailed C R Kennedy this afternoon re repairs if possible (still waiting on a reply). This has been my main lens over the last 3 1/2 years and I will be lost without it. I have been trying to save enough to get either a 70-200 F4 IS canon or 70-200 F2.8 OS sigma (F2.8 canon is way out of budget) to take over the motorsport shooting but that will have to go on the back burner now, (again). Has anyone had similar problems and found a simpler (cheaper) solution.