This also affects my Dell Inspiron 6400, also with an ATI chipset - after installing the update X doesn't start with either fglrx or vesa as the driver, giving a "No devices detected" error as in the log above.
You can get X running again by downgrading: sudo apt-get install xserver-xorg-core=1:1.0.2-0ubuntu10 sudo /etc/init.d/gdm restart FYI this is with the 2.6.15-26-686 and a dump of lspci is attached -- 1:1.0.2-0ubuntu10.3 breaks HP nx6125 https://launchpad.net/bugs/57153 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs