Comment 1 for bug 44864

solution: correct 1680x1050 resolution obtained
dapper drake kubuntu on dell inspiron 6400 WSXGA+.

procedure:
install 915 resolution via adept manager
mimic the procedure decribed in https://wiki.ubuntu.com/i915Driver

run "sudo 915resolution -l"
Pickup an unused resolution ('4d' for me)
run "sudo 915resolution 4d 1650 1050 32"

Edit /etc/X11/xorg.conf
(a nice way of doing it is with konqueror on file xorg.conf right click and select "actions" and the "edit as root")

add in the section:
 Section "Device"
 identifier "Intel Corporation Mobile Integrated Graphics Controller"
the following line:

Option "ForceBIOS" "1920x1440=1680x1050"

and in the section:
Section "Monitor"
  identifier "Generic Monitor"
the following lines:

  modeline "1680x1050@60" 147.14 1680 1784 1968 2256 1050 1051 1054 1087 -hsync +vsync
  modeline "1680x1050@75" 188.07 1680 1800 1984 2288 1050 1051 1054 1096 -hsync +vsync

add to /etc/init.d/bootmisc.sh, before the last line ": exit 0"
/usr/sbin/915resolution 4d 1680 1050 32

add to /etc/default/915resolution

MODE=4d
# and set resolutions for the mode.
XRESO=1680
YRESO=1050

restart the computer and it should work.

Do not modify the display with System Settings because it will replace the xorg.conf file modified above. solution: correct 1680x1050 resolution obtained
dapper drake kubuntu on dell inspiron 6400 WSXGA+.