Após várias pesquisas, finalmente consegui.
Ubuntu 8.10 (CCE J44MA)
No root, dei esse comando:
gedit /etc/X11/xorg.conf
Alterei o xorg como se encontra abaixo:
# xorg.conf (X.Org 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.
#
# Note that some configuration settings that could be done previously
# in this file, now are automatically configured by the server and settings
# here are ignored.
#
# 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 "Device"
Identifier "Configured Video Device"
Driver "vesa"
EndSection
Section "Monitor"
Identifier "Configured Monitor"
HorizSync 30 - 63
VertRefresh 50 - 75
EndSection
Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
EndSection
Usei as teclas Ctrl + Alt + BackSpace, mas as alterações não foram implantadas.
Reiniciei o notebook e... as resoluções estavam disponíveis no Sistema/ Preferências / Resolução de tela
Obrigado a TODOS que postaram suas dicas... tentei todas e acabei por conseguir.
Valeu!!!