setEnable do not work with CCMenuItemImage

I was doing an expandable menu, and the ZOrder of the touch into the ccMenuItemImage is not working. To create a workaround I simply was trying to just enable the menu items that are suitable after the expansion, unfortunately I could not make the method setEnable to work, I am doing this by calling _isEnable = bool; (what IMO is wrong :P).

I tried to debug but could not find where it was broken… I am using WebStorm 6.0.1 and it could not also autocomplete the method.