In my limited experience with autoshifting, it occurs when there is too much chain wrap on the rear derailleur pulleys, increasing the pull on the shift lever. This is often caused by too short of a chain, but the root cause and fix has always been to make sure the screw on the shifter is tight. I've never had to change the washers to fix that specific problem. I don't ride as hard as Chuck, so I don't worry too much about flexing the frame. After my bulk gets settled in, the max flex point is usually reached anyway. Lou Deeter, "my bike may be flexible, but I'm not" Orlando FL