Maybe your CPU is too powerfull... I forget to ask to do not re-click in the same thumbs all time, but in its neighbors too... All my friends who try it has confirmed the FPS decreasing...
On my computer, when i focus a thumbs of my 3rd level, I have 20-22 FPS... After 10-15 crazy click, i fall to 10 FPS (it's regular) I don't solve this, but i found an other way to do what i wan't... Now, I make only one instance of my movieClip, so it's the same which is applied on all thumbs when they are targeted... I add function on this movieclip to change itself... ==> It is a success, my CPU thanks me :) Maybe i was stupid to believe that " = null" was enough to relieve CPU.. ? Tanks for your answer Alexandre.
