Windows 7: No Taskbar Thumbnail Preview for Adobe Flash

Whenever I go to a website such as YouTube or Hulu to watch a Flash-based video, my taskbar thumbnail doesn't show the video. Instead, there is just a white space where the video should be. But the strange thing is that this only happens on browsers other than Internet Explorer.



I've tried 32-bit Firefox and Chrome, as well as 64-bit Firefox, and neither of those browsers display a preview. But when I run 64-bit Internet Explorer, it displays the active video inside the thumbnail preview. It doesn't matter if the video is playing or paused.

I've installed the 64-bit Adobe Flash ActiveX software as well as the 64-bit Adobe Flash plugin software. I've re-installed both software packages (ActiveX & plugin), but the situation is still the same. This seems to be a fault with the Flash plugin, not the ActiveX.

I've attached some screenshots to help visualize what I'm talking about.

Does anyone else notice this? Is this working as intended, or is this a problem?