Integrity –
You didn’t mention which browser you were using, but I use Firefox and I had this happening to me at one time. Turned out it was an extension I had installed that blocked flash and to see it all you had to do was double click on it to see it.
If you are using Firefox, you might want to check your installed extensions for Flashblock or similar extension.
I also use IE and have all the latest updates and am not experiencing this problem at all. If you are using IE and have installed some sort of toolbar this could be the culprit.