Overscrolling and 'bouncing' the page with arrow keys causes rendering glitch.

[samuknet]

When scrolling beyond the top or bottom of a page with the up/down arrow keys, holding down the arrow key causes a graphical glitch to occur when the page does the bounce effect.

To replicate, just load a page with a scroll like this one and hold down the up arrow key to scroll beyond the top edge of the page.

[nox]

I can't reproduce this.