sorry for the late reply, I didn't see yours previously.

You should assign the action to the respective event (at the top of 
the mapping tab), wheras you should choose the right version of event 
for the activation of a Behaviour. There're three - for manual 
activation, for automatic activation (app is active application) and 
for background activation (app is not active application, but runs and 
it was indicated that it is of interest to the user to control it 
nonetheless - f.ex. true for iTunes).

Best regards, 
Felix Schwarz