ATI driver problem after upgrade to Intrepid Ibex from Hardy

First, you can't open X with old driver. If you change Driver "fglrx" to "vesa", it will work without 3D effect.

The error in Xorg.0.log is:

(EE) module ABI major version (0) doesn't match the server's version (1)
(II) UnloadModule: "dri"
(II) Unloading /usr/lib/xorg/modules/extensions//libdri.so
(EE) Failed to load module "dri" (module requirement mismatch, 0)

The solution is :

sudo apt-get install envyng-core
sudo envyng -t

choose to remove all ati drivers

Then change xorg.conf to
Section "Device"
Identifier "Configured Video Device"
Driver "radeon"
EndSection

Then go to System-> Preference -> Appearance

Enable the 3D effect in one tab. The system will install the driver for you automatically.

Enjoy it:)

I think the key is remove old ATI drivers.