I can confirm this bug as well on Intel x3100 graphics. Also, there seems to be some confusion here between xorg and xserver-xorg-core:
The problematic package is xserver-xorg-core. Lenny: 1.4.2-10 Squeeze: 1.4.2-11 Sid: 1.4.2-11 Experimental: 1.5.99.902-1 xorg is the one with the 7.x versions.