Yeah that is the exact behavior I saw in the forums before. After inserting isoparms the manipulator freezes. I use nurbs alot and do not eer recall seeing this so I will have to do some research to see what causes it.

Have you tried rebuilding the surface using the cv's checkbox and deleting history?

This is not a terrible solution as it would force you to reparameterize your mesh and I am just looking for anything that might affect the behavior you are seeing.