Since the video mode you want is not listed, you'll have to override one of the available options.
This may take some serious trial-and-error testing to see which one works for you.
here is what you do...
Print out that list, because you will need to drop down to text mode for this.
open a terminal
su to root
init 3
This will drop you down to text only.
I would say you can start with mode 4b, 4d, 5a, and 5c.
if none of those work, you can try any other ones close to the ones I listed for you.
The way you do it is...at the prompt.. loged in as root, you execute this command.
915resolution <mode_id> <horiz_size> <vert_size> <color_depth>
so.... for example... to set your mode 4b, you would do.
915resolution 4b 1400 1050 32
After that, you want to start the gui to see if it works or not.
you can simply issue
startx
if it doesn't work, just press CTRL+ALT+BackSpace to exit the GUI and go back to text mode.
Try another method...
repeat until you find the one that works.
Remember, for this to work, your "Driver" line in /etc/X11/xorg.conf must be set to either "intel" or "i810"
Once you find the one combination that works, post back and I'll tell you how to automagically make it work every time you start the computer.
You can find more info at this guide
http://www.geocities.com/stomljen/readme.html