(Opened a support ticket with this information and with a small application to show this behaviour)
I'm having what I think is a strange behaviour, probably is something I'm doing wrong.
As I stated in the thread title, when I click on a tree item both cellTemplate and ItemTemplate appear, so If I click on an item two lines appear, the 1st being the CellTemplate representation and the 2nd line the ItemTemplate representation. (attch: double.jpg).
This is the code that I'm using: