On my machine (Geforce 8600GT, 171.06 drivers), scrolling on that example page (http://shame.tuxfamily.org/repo/?cat=1
) makes the X server CPU usage go up a lot and everything becomes fairly unresponsive. Setting to InitialPixmapPlacement=0 with Geforce 8600GT makes it less slow, but Firefox itself is then slow with it instead. The X server doesn't do anything abnormal or stop responding in that case. It seems like Firefox must be exposing a regression in the driver's logic in that case.