The sketch for Extrude2 has two small radii, the position of which I cannot constrain.  Any attempt to constrain them results in an overconstrained sketch.  I can pull them with the mouse but they will not be constrained.  Those features had square ends originally and they were constrained correctly. Changing them to round ends has caused the problem.  You will see that the top pattern is correctly constrained.

I know I can delete the offending parts of the sketch and recreate them but I would really like to know why this sketch won't constrain.