Hi, I'm a newb... so any help would be much appreciated. I can't quite see what I'm doing wrong. I am trying to follow a tutorial, I have created new isoparms, and clicked insert new isoparms, when I go back to control vertex, I can choose the new isoparms but when I try move them, or scale them they won't move. The box and axis lines become intermittent instead perfectly formed.

I am using maya 2009 on a mac. Any help would be amazing, thanks guys.