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?
/var/log/Xorg.0.log
and mention your model name.