Air Mobile Random Lag With DisplayList Adobe Scout

Hello,

I actually develop a game for mobile with adobe air.

My framerate is at 60 Fps.

The game works very well on PC but on mobile there is a random lag which cause performance issue.

I have corrected most of performance problems with Adobe Scout but here, this is really random :

A Movie Clip can take 1ms to rendering while 100 Frames and suddenly for one frame it's take 18ms !

This problem occurs with any MovieClip.

This is a capture of Adobe Scout to view the problem :

As my game is constantly on scrolling this is hassle.

Can someone help me ?

Thanks !