Rozlisenie obrazovky

Dobrý den, potreboval by som poradit, som zaciatocnik, mam linux ubuntu, notebook compaq evo610, grafiku Ati mobility radeon 7500, ktoru mi naslo, vsetko v poho, len nejde vobec nastavit mensie rozlisenie monitora
Mam nastavene 1400x1050, a chcem mensie, skusal som rozne rady ako zmenit xorg.conf, ale sudo kate, sudo nano, atd........ked sa mi podari zmenit, tak mi nenastartuje graficke rozhranie,vypise nejaku chybu, ako prilis vela argumentov, vypli sme Xserver..... som z toho dost zufaly, lebo pozerat na web v takom rozliseni na 14 monitore nie je ziadna slast.

Prikladam vypis z mojho xorg.conf:

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 xorg.conf manual page.
# (Type "man 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"
EndSection

Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "pc105"
Option "XkbLayout" "sk"
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 "Synaptics Touchpad"
Driver "synaptics"
Option "SendCoreEvents" "true"
Option "Device" "/dev/psaux"
Option "Protocol" "auto-dev"
Option "HorizEdgeScroll" "0"
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 "ATI Technologies Inc Radeon Mobility M7 LW [Radeon Mobility 7500]"
Driver "ati"
BusID "PCI:1:0:0"
EndSection

Section "Monitor"
Identifier "Generic Monitor"
Option "DPMS"
EndSection

Section "Screen"
Identifier "Default Screen"
Device "ATI Technologies Inc Radeon Mobility M7 LW [Radeon Mobility 7500]"
Monitor "Generic Monitor"
DefaultDepth 24
SubSection "Display"
Modes "1400x1050"
EndSubSection
EndSection

Section "ServerLayout"
Identifier "Default Layout"
Screen "Default Screen"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"

# Uncomment if you have a wacom tablet
# InputDevice "stylus" "SendCoreEvents"
# InputDevice "cursor" "SendCoreEvents"
# InputDevice "eraser" "SendCoreEvents"
InputDevice "Synaptics Touchpad"
EndSection