AS3 Time offsets "Clumping together" after window switching

Imagine you have 100 tweens. Each tween is simply an element (circle) that goes up, and then comes down again. By delaying each tween a bit from the previous, a sine wave effect is created.

Now all this is working fine. The problem arises when you switch to another window or application, and then view the window with animation again. Then the time-offsets between the 开发者_StackOverflow中文版tweens are gone, and there are a bunch of straight lines moving up and down instead of a sine wave .... The more you switch between windows, the more they "clump together" ...

I suspect there is some processor scheduling or something ike that causing the 'clumping' ...

Does anyone know what exactly is going on and is there something you can do about it ?

Do you remove your EventListeners after resetting? If not, your method could be called multiple times and could cause the "clumping".

If you do so, please show your code, so that we can have a look.