Was working fine before i played around with NVIDIA drivers and ended up with this problem. I tried running it through the terminal and i see these messages:

subsharm@subsharm-ThinkPad-T61:~$ supertuxkart
Irrlicht Engine version 1.7.2
Linux 3.0.0-15-generic #25-Ubuntu SMP Mon Jan 2 17:44:42 UTC 2012 x86_64
[FileManager] Data files will be fetched from: '/usr/share/games/supertuxkart/'
[IrrDriver] Creating NULL device
Irrlicht Engine version 1.7.2
Linux 3.0.0-15-generic #25-Ubuntu SMP Mon Jan 2 17:44:42 UTC 2012 x86_64
[IrrDriver] Trying OpenGL rendering.
[IrrDriver] Tring to create device with 32 bits
Xlib:  extension "GLX" missing on display ":0.0".
[IrrDriver Temp Logger] Level 1: No GLX support available. OpenGL driver will not work.
[IrrDriver Temp Logger] Level 2: Fatal error, could not get visual.
Segmentation fault


subsharm@subsharm-ThinkPad-T61:~$ sudo Xorg -configure
[sudo] password for subsharm: 
Fatal server error: Server is already active for display 0 
If this server is no longer running, remove /tmp/.X0-lock and start again.