Action.setLabel() doesn't work?!

i have a problem with my general actions. I want to change the label during runtime programmatically. In my ActionController I get the action, which was executed, as a parameter and i want to change the label of this action via “action.setLabel()”. It seems that the label will be changed internally when I check it via getLabel() but in the menu bar it’s still the original one, which is defined in the plugin.xml.

Same problems for other methods like setEnabled. If it’s set to false the action won’t be executed but the menu action is not grayed out or something.

I’m using VP Suit 5.1 with VP SE UML 8.1 with SP1 (build sp1_20110419) under OSX (same problems with windows version).