Outside knee pain probably means that your cleats are in the wrong place on your shoes. Your knees are probably being forced into an unnatural position. You might want to try moving them around some to see if you can alleviate the problems, or switch pedals. FWIW, I had knee pains when I rode SPDs, but it went away when I switched to a pedal with a bit more float (road 225 miles this saturday with no pain other than muscle soreness).