I discovered a bug in flash player which is quite hard to debug if you don’t have a mac. It’s got to do with mouseX values going crazy on macs. It occurs in Safari, Firefox and most likely on IE.
MY issue was that i had parralax scrolling in place. Parralax scrolling was repositioning background and content based on mouseX value.
Now when a user clicks away from the browser to any other application mouseX valuse goes mental. I was getting something like -1787232.
Apparently Adobe is already working on it, but when is it going to be realeased is unknown. Quick fix for this would be to wrap whatever you are doing by checking if the mouseX value is actually within the stage:
if (mouseX > 0 && mouseX < stage.stage.width)
{
// do stuff
}
You obviuosly need to make sure you have access to stage as well.
I hope that helps. It is really painfull to fix if you don’t have access to a mac and even if you do you would probably need to install FF, content debugger, flash tracer, etc. etc. Remembering this will save you from all of that 
A really good solution to do this is to use this snippet to check if the mouse is on the stage area:
http://www.rblab.com/blog/2009/07/as3-snippet-detect-if-mouse-pointer-is-overout-of-the-stage-area/
Use MOUSE_LEAVE!
nice man, still a problem in Flash Player… hope they’ll fix it
Which WP theme are you using?
In this issue I’m having continuous problems, please provide more detailed information.
Very great finding to me.
I am suffering a disappearance of flash content issue as well.
Finally solve that issue. Support!