depending on what your graphics card is
--- nVidia ---
the nVidia Display Settings
( applications / System Tools ) or
Livna Display Configuration ( System / Administration )
-- ati --
i don't have one
-----
or edit your /etc/X11/xorg.conf
there should be a section like this one
Code:
Section "Screen"
Identifier "Screen0"
Device "Videocard0"
Monitor "Monitor0"
DefaultDepth 24
Option "UseEvents" "False"
Option "RenderAccel" "True"
Option "Composite" "Enable"
Option "AddARGBGLXVisuals" "true"
Option "metamodes" "1024x768 +0+0; 800x600 +0+0; 640x480 +0+0"
Option "NVAGP" "3"
SubSection "Display"
Depth 24
Modes "1024x768" "832x624" "800x600" "720x400" "640x480" "640x400" "640x350"
EndSubSection
EndSection
add 1024x768 to it as the FIRST one
-- example--
Option "metamodes" "1024x768 +0+0; 800x600 +0+0; 640x480 +0+0"
Modes "1024x768" "832x624" "800x600" "720x400" "640x480" "640x400" "640x350"
that should do it