Getting better resolution on OpenSolaris.2009.06?

Question

I am running OpenSolaris.2009.06 on Dell PowerEdge T410 server (x86 machine). It has Matrox G200 video card. Currently I am getting a maximum of 1024 * 800 screen resolution. There is no xorg.conf file under /etc/X11. Moreover, I am unable to find drivers for G200 card either using Google or Matrox webssite. My 26'' LCD display can support more than (1024 * xx ) resolution. Therefore, I have created xorg.conf file with the following details. However, with the xorg.conf file, the maximum screen resolution I am getting is 840*600. I think that something wrong with the xorg.conf file. To get at least the default (1024 * xx) resolution, I have needed to delete the xorg.conf file and restart the GDM. Could anyone help me to get a better screen resolution, please? BTW, I have also posted this question on opensolaris forum, but there is no response.

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

Section "Files"
    FontPath        "/usr/X11R6/lib/X11/fonts/misc/:unscaled"
    FontPath        "/usr/X11R6/lib/X11/fonts/100dpi/:unscaled"
    FontPath        "/usr/X11R6/lib/X11/fonts/75dpi/:unscaled"
    FontPath        "/usr/X11R6/lib/X11/fonts/misc/"
    FontPath        "/usr/X11R6/lib/X11/fonts/100dpi/"
    FontPath        "/usr/X11R6/lib/X11/fonts/75dpi/"
    FontPath        "catalogue:/etc/X11/fontpath.d"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/mouse"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5 6 7"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Keyboard0"
    Driver         "keyboard"
EndSection

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       28.0 - 33.0
    VertRefresh     43.0 - 72.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Card0"
    Driver         "vesa"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
        ViewPort    0 0
            Depth   24
            Modes   "1280x1024_60.00" "1440x900_60.00" "1024x768_75.00" "800x600_75_00" "640x480_60.00"
    EndSubSection
EndSection