Comment 22 for bug 188792

The user isn't specifying anything in their xorg.conf; it's just a stock empty config file (see below). Here's an updated description of the problem:

"I measured my screen. The viewing area is 32cm wide and like 25 and a
half cm tall.
This 1280x960 stetches everything vertically and leaves two big black
strips up the side of the screen. You'd think it would do the
opposite.."

So it sounds like the driver (or server) is picking an inappropriate modeline.

# 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.
#
# 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 "InputDevice"
 Identifier "Generic Keyboard"
 Driver "kbd"
 Option "XkbRules" "xorg"
 Option "XkbModel" "pc105"
 Option "XkbLayout" "us"
EndSection

Section "InputDevice"
 Identifier "Configured Mouse"
 Driver "mouse"
 Option "CorePointer"
EndSection

Section "Device"
 Identifier "Configured Video Device"
EndSection

Section "Monitor"
 Identifier "Configured Monitor"
EndSection

Section "Screen"
 Identifier "Default Screen"
 Monitor "Configured Monitor"
 Device "Configured Video Device"
EndSection

Section "ServerLayout"
 Identifier "Default Layout"
 Screen "Default Screen"
EndSection