Using projector on D630 (debian lenny+xfce)?

Hi guys:

I have debian lenny 2.6.24 and xfce4 on my laptop(DELL D630) and I'm trying to connecting the projector to my laptop, but it didn't work.
The video card on my laptop is:
01:00.0 VGA compatible controller [0300]: nVidia Corporation Quadro NVS 135M [10de:042b] (rev a1)

When I connected the projector, I pressed Fn+F8 just same as I do on Windows, but nothing happened.

It seems that it could not detect the projector (or monitor, I also tried to connecting to a separate monitor), the output of the command is always as below (I put it at the end of this post to save space here):

I just wonder if anyone has the experience on this? How can I get this to work?
Do I need to install any additional drivers or sth? I also appended my xorg.conf for your check.
Thanks so much!

michael@debian: ~$ xrandr
Screen 0: minimum 320 x 240, current 1280 x 800, maximum 1280 x 800
default connected 1280x800+0+0 0mm x 0mm
   1280x800       50.0*
   1024x768       51.0
   800x600        52.0
   800x512        53.0
   720x450        54.0
   700x525        55.0
   640x512        56.0
   640x480        57.0     58.0
   640x400        59.0
   640x384        60.0
   512x384        61.0
   400x300        62.0
   320x240        63.0

xorg.conf:
# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 1.0 (buildmeister@builder63) Thu Apr 10 18:52:28 PDT 2008

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

Section "Files"
    RgbPath         "/usr/lib/X11/rgb"
    FontPath        "/home/michael/.fonts"
EndSection

Section "Module"
    Load           "dbe"
    Load           "extmod"
    Load           "type1"
    Load           "freetype"
    Load           "glx"
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       30.0 - 110.0
    VertRefresh     50.0 - 150.0
    Option         "DPMS"
EndSection

Section "Device"

## for compiz
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
        Option "BIOSHotkeys" "on"
EndSection
Section "Screen"
Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "AddARGBGLXVisuals" "True"
    Option         "XAANoOffscreenPixmaps" "true"
    Option         "RenderAccel" "true"
    Option         "AllowGLXWithComposite" "true"
    Option         "TripleBuffer" "true"
## for projector
    Option         "MonitorLayout" "CRT,LFP"
    Option         "Clone" "true"
    Option         "DevicePresence" "true"
    Option         "CheckLid" "false"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Extensions"
    Option         "Composite" "true"
EndSection
Section "Screen"