Ubuntu – How to get the third screen (laptop + two monitors) running on w/ nvidia drivers

I've got a laptop with GeForce GTX 560M and I'm using the nvidia drivers on Ubuntu 11.10 to support the a second monitor with twinview, which works fine.

When I run nvidia-settings, and connect my third monitor (counting the laptop display), nvidia-settings freezes indefinitely if I select to use it as twinview, too. If I choose to display it as a separate X Screen, save the settings, and restart, that setting is never applied. Here is the Xorg.conf created by nvidia on save:

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings:  version 285.05.09  (buildd@allspice)  Wed Nov 16 15:25:12 UTC 2011

# commented out by update-manager, HAL is now used and auto-detects devices
# Keyboard settings are now read from /etc/default/console-setup
#Section "InputDevice"
#
#    # generated from default
#    Identifier     "Mouse0"
#    Driver         "mouse"
#    Option         "Protocol" "auto"
#    Option         "Device" "/dev/psaux"
#    Option         "Emulate3Buttons" "no"
#    Option         "ZAxisMapping" "4 5"
#EndSection
# commented out by update-manager, HAL is now used and auto-detects devices
# Keyboard settings are now read from /etc/default/console-setup
#Section "InputDevice"
#
#    # generated from default
#    Identifier     "Keyboard0"
#    Driver         "kbd"
#EndSection

Section "ServerLayout"

    # Keyboard settings are now read from /etc/default/console-setup
    #    InputDevice    "Keyboard0" "CoreKeyboard"
    # commented out by update-manager, HAL is now used and auto-detects devices
    # Keyboard settings are now read from /etc/default/console-setup
    #    InputDevice    "Mouse0" "CorePointer"
# Removed Option "Xinerama" "0"
# Removed Option "Xinerama" "1"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    Screen      1  "Screen1" RightOf "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
    Option         "Xinerama" "0"
    # commented out by update-manager, HAL is now used and auto-detects devices
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
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 "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "LEN"
    HorizSync       56.5 - 67.8
    VertRefresh     40.0 - 60.0
    Option         "DPMS"
EndSection

Section "Monitor"
    Identifier     "Monitor1"
    VendorName     "Unknown"
    ModelName      "Samsung SyncMaster"
    HorizSync       30.0 - 81.0
    VertRefresh     56.0 - 75.0
    Option         "DPMS"
    # HorizSync source: edid, VertRefresh source: edid
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GTX 560M"
    Option         "NoLogo" "True"
    BusID          "PCI:1:0:0"
    Screen          0
EndSection

Section "Device"
    Identifier     "Device1"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GTX 560M"
    BusID          "PCI:1:0:0"
    Screen          1
EndSection

Section "Screen"

    # Removed Option "metamodes" "DFP-0: nvidia-auto-select +0+0"
# Removed Option "metamodes" "DFP-0: nvidia-auto-select +0+0, DFP-2: nvidia-auto-select +1920+0"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "TwinView" "1"
    Option         "TwinViewXineramaInfoOrder" "DFP-0"
    Option         "metamodes" "DFP-0: 1920x1080 +0+0, DFP-2: 1680x1050 +1920+0; DFP-0: 1920x1080 +0+0, DFP-2: NULL"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Screen"

# Removed Option "metamodes" "DFP-2: nvidia-auto-select +0+0"
# Removed Option "metamodes" "DFP-1: nvidia-auto-select +0+0"
# Removed Option "metamodes" "DFP-1: 1680x1050 +0+0"
# Removed Option "metamodes" "DFP-1: nvidia-auto-select +0+0"
    Identifier     "Screen1"
    Device         "Device1"
    Monitor        "Monitor1"
    DefaultDepth    24
    Option         "TwinView" "0"
    Option         "metamodes" "DFP-1: 1680x1050_60 +0+0"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Extensions"
    Option         "Composite" "Disable"
EndSection

I'm not very handy with X config. Am I doing something wrong?