I have an ASUS N76VZ laptop with 12.2 openSUSE and GeForce GT650M card. I found that KDE doesn't allow me to use OpenGL rendering. I tried to install nVidia's driver from script but once it writes the xorg.conf file I'm unable to boot desktop. I have the following errors in system log

Oct 30 08:28:13 RAYNOR kdm[2727]: X server died during startup
Oct 30 08:28:13 RAYNOR kdm[2727]: X server for display :0 cannot be started, session disabled

I noticed that the /etc/X11/xorg.conf backup file was empty, so I renamed the new xorg.conf and left none: the desktop booted!!!

How can I fix OpenGL rendering with or without driver installation?

[Update]: Xorg.0.log says

[  1434.207]    compiled for 4.0.2, module version = 1.0.0
[  1434.207]    Module class: X.Org Server Extension
[  1434.207] (II) NVIDIA GLX Module  304.60  Sun Oct 14 20:44:54 PDT 2012
[  1434.207] (II) Loading extension GLX
[  1434.207] (II) LoadModule: "record"
[  1434.207] (II) Loading /usr/lib64/xorg/modules/extensions/librecord.so
[  1434.207] (II) Module record: vendor="X.Org Foundation"
[  1434.207]    compiled for 1.12.3, module version = 1.13.0
[  1434.207]    Module class: X.Org Server Extension
[  1434.207]    ABI class: X.Org Server Extension, version 6.0
[  1434.207] (II) Loading extension RECORD
[  1434.207] (II) LoadModule: "dri"
[  1434.207] (II) Loading /usr/lib64/xorg/modules/extensions/libdri.so
[  1434.207] (II) Module dri: vendor="X.Org Foundation"
[  1434.207]    compiled for 1.12.3, module version = 1.0.0
[  1434.207]    ABI class: X.Org Server Extension, version 6.0
[  1434.207] (II) Loading extension XFree86-DRI
[  1434.207] (II) LoadModule: "nvidia"
[  1434.208] (II) Loading /usr/lib64/xorg/modules/drivers/nvidia_drv.so
[  1434.208] (II) Module nvidia: vendor="NVIDIA Corporation"
[  1434.208]    compiled for 4.0.2, module version = 1.0.0
[  1434.208]    Module class: X.Org Video Driver
[  1434.208] (II) NVIDIA dlloader X Driver  304.60  Sun Oct 14 20:24:42 PDT 2012
[  1434.208] (II) NVIDIA Unified Driver for all Supported NVIDIA GPUs
[  1434.208] (++) using VT number 8

[  1434.320] (EE) No devices detected.
[  1434.320] 
Fatal server error:
[  1434.320] no screens found
[  1434.320] 
Please consult the The X.Org Foundation support 
         at http://wiki.x.org
 for help.