Error: This application requires shockwave player 8....

Hello,

The following error message pops up reguarly when running various programs
like:

PcCillin (while scanning)
WindowsXP update
Windows disk clean up utility

But also sometimes when windows has just loaded.

"This application requires the shockwave 8 player, which is not installed.
Click OK to download it"

Now, when this error appears, at the moment i move the mouse it disappears
again. So i can't even click OK or Cancel.
Also when it shows up, the windows taskbar disappears and appears again when
the error is gone.

I have the latest version of shockwave, videocard driver and directX installed.

Thanks for any help.