What's wrong with ADDED_TO_STAGE?

What's wrong with ADDED_TO_STAGE?
I'm expexcting to get this:
lvl1 added to stage
lvl2 added to stage
lvl3 added to stage
but I don't...
ADDED_TO_STAGE gets fired several time without trigerring REMOVED_FROM_STAGE...
Am I missing something?
気になる
