Reinstall/Upgrade ATI Radeon 3xxx driver on CentOS5

1. find latest driver from amd.com
2. backup /etc/X11/xorg.conf
3. uninstall existing driver by invoke command /usr/share/ati/fglrx-uninstall.sh
4. run the .run script . i.e ati-driver-installer-8-12-x86.x86_64.run
5. test it: startx.
6. revert run level to 5, if it was set to 3 for troubleshooting.

but still has problem with Xen kernel. it just hang a while and auto-reboot computer.

As workaround, I use default xorg.conf or just delete it. The impact is resolution can be 1400x1050, instead of optimized 1680x1050.

Hope :
I proceed to play Xen successfully
New few future driver/kernel can fix the problem. Otherwise , have to change graphic card .
Sigh