Bad Video signal

Hello!
I found some troubles with the graphic configuration in Kubuntu
6.10, which I have just installed.
My graphic card is a Matrox G550 Dual Head with an analog output (VGA) and
a digital one (DVI-D single link). Using Windows, like during the first
operations (RAM test, boot, ecc.) the monitor can receive the digital
signal by the DVI cable and it regularly functions.
When I choose Linux in the boot menù the trobles begins. The monitor says
"out of range, 29.5 - 30.7 Hz". Only the analog signal is ok.
So I would have solved this problem, by going with KDE Graphic Interface in
System / Graphic card - monitor (these voices are similar to the original
ones, which I don't remember exactly; but the meaning is the same); I saw
that graphic card was configured as follows:

Graphic card
mga
Monitor: Primary (0)

Graphic card
Matrox G550 Dual Head
Monitor: Secondary (1)

This is ok. But I wanted to use permanently the DVI signal, so I tried to
modify this parameters in this way:

Graphic card
mga
Monitor: Secondary (1)

Graphic card
Matrox G550 Dual Head
Monitor: Primary (0)

Now, after I selection "Linux" in the Grub boot menù, I can't see no the
analog video, nor the DVI.
I could copy xorg.conf from Windows and I write it some lines below, if you
can help me.
Why does Linux see two graphic cards?
How can modify these settings to recover?
Thank you if you can reply!

Rocky3


Ecco il file

# /etc/X11/xorg.conf (xorg X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool,
using
# values from the debconf database.
#
# Edit this file with caution, and see the /etc/X11/xorg.conf manual page.
# (Type "man /etc/X11/xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades
*only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically
updated
# again, run the following command:
# sudo dpkg-reconfigure -phigh xserver-xorg

Section "Files"
FontPath "/usr/share/X11/fonts/misc"
FontPath "/usr/share/X11/fonts/cyrillic"
FontPath "/usr/share/X11/fonts/100dpi/:unscaled"
FontPath "/usr/share/X11/fonts/75dpi/:unscaled"
FontPath "/usr/share/X11/fonts/Type1"
FontPath "/usr/share/X11/fonts/100dpi"
FontPath "/usr/share/X11/fonts/75dpi"
FontPath "/usr/share/fonts/X11/misc"
# path to defoma fonts
FontPath "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
EndSection

Section "Module"
Load "i2c"
Load "bitmap"
Load "ddc"
Load "extmod"
Load "freetype"
Load "int10"
Load "type1"
Load "vbe"
load "glx"
load "GLcore"
load "dri"
load "v4l"
EndSection

Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
option "CoreKeyboard"
option "XkbRules" "xorg"
option "XkbModel" "pc105"
option "XkbLayout" "it"
option "XkbOptions" "lv3:ralt_switch"
EndSection

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

Section "InputDevice"
Driver "wacom"
Identifier "stylus"
option "Device" "/dev/wacom"# Change to
option "Type" "stylus"
option "ForceDevice" "ISDV4"# Tablet PC ONLY
# /dev/input/event
# for USB
EndSection

Section "InputDevice"
Driver "wacom"
Identifier "eraser"
option "Device" "/dev/wacom"# Change to
option "Type" "eraser"
option "ForceDevice" "ISDV4"# Tablet PC ONLY
# /dev/input/event
# for USB
EndSection

Section "InputDevice"
Driver "wacom"
Identifier "cursor"
option "Device" "/dev/wacom"# Change to
option "Type" "cursor"
option "ForceDevice" "ISDV4"# Tablet PC ONLY
# /dev/input/event
# for USB
EndSection

Section "Device"
identifier "Matrox Graphics, Inc. MGA G550 AGP"
boardname "mga"
busid "PCI:1:0:0"
driver "mga"
screen 0
EndSection

Section "Monitor"
identifier "Generic Monitor"
vendorname "Plug 'n' Play"
modelname "Plug 'n' Play"
modeline "640x480@60" 25.2 640 656 752 800 480 490 492 525 -vsync -hsync
gamma 1.0
EndSection

Section "Screen"
Identifier "Default Screen"
Device "Matrox Graphics, Inc. MGA G550 AGP"
Monitor "Generic Monitor"
DefaultDepth 24
SubSection "Display"
depth 24
virtual 640 480
modes "640x480@60"
EndSubSection
EndSection

Section "ServerLayout"
Identifier "Default Layout"
screen 0 "screen2" 0 0
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
InputDevice "stylus" "SendCoreEvents"
InputDevice "cursor" "SendCoreEvents"
InputDevice "eraser" "SendCoreEvents"
EndSection

Section "DRI"
Mode 0666
EndSection
Section "device" #
identifier "device1"
boardname "mga"
busid "PCI:1:0:0"
driver "mga"
screen 1
EndSection
Section "screen" #
identifier "screen1"
device "device1"
defaultdepth 24
monitor "monitor1"
EndSection
Section "monitor" #
identifier "monitor1"
gamma 1.0
EndSection
Section "device" #
identifier "device2"
boardname "Matrox Millennium G550 DualHead"
busid "PCI:3:0:0"
driver "mga"
screen 0
vendorname "Matrox"
EndSection
Section "screen" #
identifier "screen2"
device "device2"
defaultdepth 24
monitor "monitor2"
EndSection
Section "monitor" #
identifier "monitor2"
gamma 1.0
EndSection
Section "ServerFlags"
EndSection


--
"Il sapere e la ragione parlano, l'ignoranza ed il torto urlano".

Arturo Graf / Indro Montanelli / Anonimo
.