Aquí la configuración:
Section "Files"
FontPath "unix/:7100" # local font server
if the local font server has problems, we can fall back on these
FontPath "/usr/share/fonts/X11/misc"
FontPath "/usr/lib/X11/fonts/misc"
FontPath "/usr/share/fonts/X11/cyrillic"
FontPath "/usr/lib/X11/fonts/cyrillic"
FontPath "/usr/lib/X11/fonts/100dpi/:unscaled"
FontPath "/usr/lib/X11/fonts/75dpi/:unscaled"
FontPath "/usr/share/fonts/X11/Type1"
FontPath "/usr/lib/X11/fonts/Type1"
FontPath "/usr/share/fonts/X11/CID"
FontPath "/usr/lib/X11/fonts/CID"
FontPath "/usr/lib/X11/fonts/Speedo"
FontPath "/usr/share/fonts/X11/100dpi"
FontPath "/usr/lib/X11/fonts/100dpi"
FontPath "/usr/share/fonts/X11/75dpi"
FontPath "/usr/lib/X11/fonts/75dpi"
EndSection
Section "Module"
Load "bitmap"
Load "dbe"
Load "ddc"
Load "dri"
Load "extmod"
Load "freetype"
Load "glx"
Load "int10"
Load "record"
Load "type1"
Load "vbe"
EndSection
Section "InputDevice"
Identifier "Generic Keyboard"
Driver "keyboard"
Option "CoreKeyboard"
Option "XkbRules" "xfree86"
Option "XkbModel" "pc105"
Option "XkbLayout" "es"
EndSection
Section "InputDevice"
Identifier "Configured Mouse"
Driver "mouse"
Option "CorePointer"
Option "Device" "/dev/input/mice"
Option "Protocol" "ImPS/2"
Option "Emulate3Buttons" "true"
Option "ZAxisMapping" "4 5"
EndSection
Section "Device"
Identifier "ATI Technologies, Inc. 3D Rage II+ 215GTB [Mach64 GTB]"
Driver "ati"
EndSection
Section "Monitor"
Identifier "Monitor genérico"
HorizSync 30-54
VertRefresh 50-120
Option "DPMS"
EndSection
Section "Screen"
Identifier "Default Screen"
Device "ATI Technologies, Inc. 3D Rage II+ 215GTB [Mach64 GTB]"
Monitor "Monitor genérico"
DefaultDepth 16
SubSection "Display"
Viewport 0 0
Depth 16
Modes "1024x768"
EndSubSection
EndSection
Section "ServerLayout"
Identifier "Default Layout"
Screen "Default Screen"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
EndSection
Section "DRI"
Mode 0666
EndSection
Y el monitor es un... Liteon A1554NE/NEL
Gracias por todo ^^