I have endlessly been playing around with the Nvidia X Server settings and changing my xorg.conf file to try and work for me and on most days its fine. In each instance I get it working for a while and then this morning the most bizarre thing happens. The moment I open any type of Wine program (which never use to be a problem) my Twin View setup disappears and am left with mirrored displays. I try and change the settings in the Nvidia driver, but its not interested and the screens remain mirrored. I have a work around. Restart my pc...

Below are the contents of my current xorg.conf file.

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings:  version 295.33  (buildd@zirconium)  Fri Mar 30 13:43:34 UTC 2012

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
    Option         "Xinerama" "0"
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"
    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "LG Electronics W1934"
    HorizSync       30.0 - 83.0
    VertRefresh     56.0 - 75.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 9400 GT"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "TwinView" "1"
    Option         "metamodes" "CRT-0: nvidia-auto-select +0+0, CRT-1: nvidia-auto-select +1440+0"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection