Hanging ATI X-Server Centrino

Problem: If on a thinkpad with ati Graphic Card dmesg shows unstable clocksource then add to /boot/grub/menu.lst

vga=normal clocksource=acpi_pm

..and install #aptitude install cpufrequtils

edit #sudo nano /etc/init.d/cpufrequtils

search "ondemand" change to "performance"

..then reboot