In a sequence diagram, select a state and the go to the Property View for that state.
Now go to "Create a new Element" (green "+") for DoActivity and select FunctionBehaviour. In the "Create a new Element" dialog, select the UML tab, enter a name and click OK.
In the diagram, the state now shows "/do OpaqueBehaviour <your entered name>.
Should it not show "/do FunctionBehaviour <your entered name>?
I tried selecting Activity and OpaqueBehaviour in place of FunctionBehaviour, suspecting an index problem but both of those work as expected.
Yes, I meant state machine and yes, I can file a bug (350446). I noticed that the problem also applies to Entry and Exit functions.
BTW where can I find a definition of the various options that are available when adding a DoActivity? Specifically, what is the difference between a FunctionBehaviour, an OpaqueBehaviour and an Activity?
One more thing. I noticed that when I exported my StateMachine diagram to a PNG, the initial state (solid circle) and the transition from the initial state to my first state were not included in the picture. Is this by design?