The infamous Error 99 message; Cannon Eos Digital Camera

Yes, the infamous error 99 message. What to do? I followed some good advice regarding a step-by-step process of elimination to find the problem, the question is how do i fix it? The first step is to leave the body of the camera without power and CF card for 20min. Then put battery in and remove lens. If it works, turn off the camera and insert the CF card. If it doesn't work up until now you should probably service your camera. if it does, turn off the camera and reattach the lense and try again. If it doesn't work you know it's the lense or the data contacts between the lens and the body (which can be easily determined with a soft cloth). So here it is; I have an 18/55mm lense that for some reason only shows the error 99 message when focusing below 24mm. is this a firmware issue or a compatability issue? or is it something else entirely? It works perfectly above 24mm in both manual and auto focus as well. please help