Here are pics of a 181 lined up against the stocky. All measurements are showing that the 181 is dead on.

I would say that woody is on the right track with his thoughts, as they possibility for the crank pully to walk like that without being corrected by one of the other accessories in the loop is slim... I have however seen that with a bad/lose guide pully or tensioner. I would suggest looking that those for play.

Remember guys, these pullies have been around quite some time in the c32 world before coming over to the crossfire boys, with the same design.