I'm having the same problem, only worse. I'm not even seeing the my test include. If I move my simple rotate action into the main script, WED still can't find it, even if I reselect it via map properties. However, if I go ahead and manually assign my simple rotate action to an entity, it builds in and runs in my test.

I'm hoping one doesn't have to add custom entries into template_6.xml to have them show up in the behaviors list!

EDITTED: Alright! Once I closed WED and reopened it, then I was able to see the include and the action as expected within the behavior selection list. I would have thought it would hae recognized it by simple by reaelecting the updated main script in the map properties dialog : )