I was having some pretty bad noise that I finally realized was coming from the Look Keo cleats. I tightened them all the way up (again) and all it did was to change where in the pedal stroke it occurred.

This is irritating since the Arc cleats didn't do this but the Keo cleats have a different shape into which it is easier to step into (using the Classic pedals - the Blades are absolutely horrible to get into because they don't rotate to the correct position. In fact, they don't rotate at all because they are so light that they cannot overcome the friction of the bearing seals.)

When you are one a hard climb on a quiet road they can drive you batty.