como Instalar dos monitores con una grafica

[Gazpachito]

hola amigos,

Mi problemilla es el siguiente, tengo 2 monitores uno de 20 pulgadas
FP202W y otro de 17" FP71+ de la marca Benq y en el ordenado tengo una
grafica Geforce 6800XT de nvidia, el problema que me encuentro es que
solo he consegido hacer funcionar los dos monitores saliendo en los dos
lo mismo pero el raton solo aparece en uno y con una resolucion de
800x600, con el driver descargado de nvia y el siguiente xorg.conf:
Section "Files"
        FontPath        "/usr/share/fonts/X11/misc"
        FontPath        "/usr/share/fonts/X11/cyrillic"
        FontPath        "/usr/share/fonts/X11/100dpi/:unscaled"
        FontPath        "/usr/share/fonts/X11/75dpi/:unscaled"
        FontPath        "/usr/share/fonts/X11/Type1"
        FontPath        "/usr/share/fonts/X11/100dpi"
        FontPath        "/usr/share/fonts/X11/75dpi"
        # path to defoma fonts
        FontPath        "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
EndSection

Section "Module"
        Load    "i2c"
        Load    "bitmap"
        Load    "ddc"
        Load    "dri"
        Load    "extmod"
        Load    "freetype"
        Load    "glx"
        Load    "int10"
        Load    "vbe"
EndSection

Section "InputDevice"
        Identifier      "Generic Keyboard"
        Driver          "kbd"
        Option          "CoreKeyboard"
        Option          "XkbRules"      "xorg"
        Option          "XkbModel"      "pc105"
        Option          "XkbLayout"     "es"
EndSection

Section "InputDevice"
        Identifier      "Configured Mouse"
        Driver          "mouse"
        Option          "CorePointer"
        Option          "Device"                "/dev/input/mice"
        Option          "Protocol"              "ImPS/2"
        Option          "ZAxisMapping"          "4 5"
        Option          "Emulate3Buttons"       "true"
EndSection

Section "InputDevice"
Identifier "Configured Mouse"
Driver "mouse"
Option "CorePointer"
Option "Dev Name" "Logitech Logitech BT Mini-Receiver"
Option "Dev Phys" "usb-0000:00:0b.1-5.2/input0"
Option "Protocol" "evdev"
Option "Buttons" "12"
Option "Emulate3Buttons" "false"
Option "ZAxisMapping" "4 5 7 6"
Option "Resolution" "800"
Option "Device" "/dev/input/event3"
EndSection

Section "InputDevice"
        Driver          "wacom"
        Identifier      "stylus"
        Option          "Device"        "/dev/input/wacom"
        Option          "Type"          "stylus"
        Option          "ForceDevice"   "ISDV4"         # Tablet PC ONLY
EndSection

Section "InputDevice"
        Driver          "wacom"
        Identifier      "eraser"
        Option          "Device"        "/dev/input/wacom"
        Option          "Type"          "eraser"
        Option          "ForceDevice"   "ISDV4"         # Tablet PC ONLY
EndSection

Section "InputDevice"
        Driver          "wacom"
        Identifier      "cursor"
        Option          "Device"        "/dev/input/wacom"
        Option          "Type"          "cursor"
        Option          "ForceDevice"   "ISDV4"         # Tablet PC ONLY
EndSection

Section "Device"
        Identifier      "nvidia0"
        Driver          "nvidia"
        BusID           "PCI:1:0:0"
        Option          "TwinView" "true"
        Screen          0
EndSection

Section "Device"
        Identifier      "nvidia1"
        Driver          "nvidia"
        BusID           "PCI:1:0:0"
        Screen          1
EndSection


Section "Monitor"
        Identifier      "BenQ FP202W"
        Option          "DPMS"
EndSection
Section "Monitor"
        Identifier      "BenQ FP71+"
        Option          "DPMS"
EndSection

Section "Screen"
        Identifier      "screen0"
        Device          "nvidia0"
        Monitor         "BenQ FP71+"
        DefaultDepth    24
        SubSection "Display"
                Depth           24
                Modes           "1280x1024" "1024x768"
        EndSubSection
EndSection

Section "Screen"
        Identifier      "screen1"
        Device          "nvidia1"
        Monitor         "BenQ FP202W"
        DefaultDepth    24
       SubSection "Display"
        Depth           24
        Modes          "1680x1050" "1280x1024" "1024x768"
        EndSubSection
EndSection
        

Section "ServerLayout"
        Identifier      "Default Layout"
        option          "Xinerama" "on"
        Screen          "Screen0"
        Screen          "Screen1" LeftOf "Screen0"
        InputDevice     "Generic Keyboard"
        InputDevice     "Configured Mouse"
        InputDevice     "stylus"        "SendCoreEvents"
        InputDevice     "cursor"        "SendCoreEvents"
        InputDevice     "eraser"        "SendCoreEvents"
EndSection

Section "DRI"
        Mode    0666
EndSection
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Y lo que quiero hacer es que el monitor de 20 pulgadas sea al principal
y extendr el monitor al de 17 para asi mientras trabajo en uno puedo ver
en el otro cosas sin tener que cambiar de escritorio o sin minimizar
nada.

Muchas gracias,