Divx and embedded webpage videos look blocky on Windows 7 64bit?

[frivolousminimalist]

I am runnign windows 7 64 bit, with a ATI 4850 video card. I have noticed blocky video in vlc and other video programs, but have been able to fix it by switching the renderer to say opengl. Still though, when using IE or firefox, all divx videos and alike have a almost watermark like boxing effect on all videos. Is there a workaround or fix for this, is there away to manual set the render for IE in the registry? I have tried uninstalling, and reinstalling divx codecs, and even large codec packs. yes i know windows 7 comes with a built in divx codec, but i thought I would try anyways. anyone have a solution to the blocky embedded video in IE and firefox?