I have the exact same problem, the pencil wont open for menu, radio groups, checkbox group, not even on lists.
Dreamweaver 5.5 windows 7 64bit, the extensions have been installed in the exact order as told here on the forums, have every single extension, power suit, and all new ones design extender and databridge to.
It also happens on the create database pages with the new dataassist not only on css form builder