Thinkpad R50p ATI xserver hanging freeze sometimes Debian Lenny

Hardware: R50p with ATI Graphic 128MB
01:00.0 VGA compatible controller: ATI Technologies Inc M10 NT [FireGL Mobility T2] (rev 80)
System: Debian Lenny 5.0
Driver: fglrx

Solution:

1. install cpufrequtils

   #sudo apt-get install cpufrequtils

2. edit

    #nano /etc/initrd/cpufrequtils

3. change line „ondemand“ to „performance“
4. check System

   #dmesg

5. System show „unstable clocksource“ last line
6. edit

    #sudo nano /etc/boot/menu.lst

7. add to Kernelparametes line /vmlinuz-2.6.26-2-686 root=/dev/hda3 ro quiet vga=normal clocksource=acpi_pm
8. ..reboot

This will run System on max. Speedstep and Videos does’nt hang X-Server.
Should help on other Thinkpads to with ATI Chip’s