Bug??!

I recently noticed something strange. I have a intro screen to my game where a object is spawned at a certain time. If I build the swf and run it in the browser it works as it should as long as I have the game open.

But if I start the game and the intro and then go to some other tab in my browser and then back to the game is seems like the clock has stopped or something because the object spawns at the wrong place??.

Why is this? Do I need to add some kind of pause feature when I lose focus on the game to prevent this or how can I do it? Why is the game not playing in the background as usual without screwing up if I go to another site?

Just checked. When you activate another window than the browser, the application continues to work.
The problem may come from activating another tab, depending on the browser. It seems that on certain browsers it pauses the application. So on the way back, the timer catches up and the objects are moved accordingly.
Dont know really how to correct that.