The problem of not getting the creationComplete event was caused by my change that added the PopUpManager.centerPopUp() call inside of PopUpManager.show(). What was happening was the pop up was created and the ?\226?\128?\156creationComplete?\226?\128?\157 event fired before the Alert was returned from Alert.show(). I think the endEffect was a similar issue.
The fix is to listen for the FlexEvent.CREATION_COMPLETE event and center the popup when that event is received.
Checkintests: Standard plus mustella Alert