I'd like to 2nd the need for a good, professional bike fit. I had some real problems w/ my left knee (it's my weak side) - I got fitted by the bike shop where I bought my bike, tried different combinations of shoes and pedals, stretched religiously, etc. Nothing seemed to help. I then went to get fitted by a shop owner that used the Lemond fit system. He made some small adjustments to my position and put some wedges under my cleats. That did it - probably the best $80 I spent on cycling...