It does this in Firefox and with various programs with web interfaces (like the World of Webcraft webpage stuff on the UI with the Play button before you enter the game itself). They're flickery sort of glitches that vanish when the page stops moving. In any case, though, this isn't my browser at work, it appears there's a bug somewhere in the 2D with my card drivers. I *think* it may have to do with the Framebuffer kext, as replacing it affected how the glitches appear. instead of a consistent but sporadic page tearing effect, I now get an equally sporadic "white-out" effect on a portion of the webpage when scrolling.
If it's the framebuffer, though, would an EFI string possibly help?

EDIT: Picture added showing the woe itself. It finally appeared while the camera was handy lol. Frogive the fuzziness as I had to scroll at the same time as I held the camera and I'm not so good at one-handed camera use. Anyway the pattern of distortion is always different but that's how it affects the screen.

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