Nvidia Quadro K2000M on Dell Precision M4700 - Drivers not working

I just did a fresh install of Ubuntu 12.04 LTS and installed the nvidia drivers from their website (304.60 Latest Long Lived Branch).

They are just not working. Resolution is down to 640x540 or something.
I run sudo nvidia-xconfig getting as result:

Using X configuration file: "/etc/X11/xorg.conf".
Backed up file '/etc/X11/xorg.conf' as
'/etc/X11/xorg.conf.backup'
New X configuration file written to '/etc/X11/xorg.conf'

but when I try to open the settings with nvdia-settings I get:

You do not appear to be using the NVIDIA X driver.  Please edit your X configuration file (just run `nvidia-xconfig` as root), and restart the X server.

Hence I restart the X server (sudo restart lightdm) but once again I get the same results.

Here is my xorg.conf file:

memecs@memecs-drz:~$ cat /etc/X11/xorg.conf

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 304.60  (buildmeister@swio-display-x86-rhel47-04.nvidia.com)  Sun Oct 14 21:34:47 PDT 2012


Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
EndSection


Section "Files"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"

    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"

EndSection

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       28.0 - 33.0
    VertRefresh     43.0 - 72.0
    Option         "DPMS"
EndSection


Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"

    Monitor        "Monitor0"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Any help is really appreciated. Thanks!

Problem solved. Need to disable optimus from BIOS. Then everything works fine.