I'll try to help, but I don't know all the right Ubuntu commands (hopefully someone can jump in and correct me).
Before editing the Xorg config file, I assume you've tried running any Preferences-type settings that can be launched from within the Desktop environment (Gnome, etc.) itself to change the res?
Assuming you have, and you've still had no luck, then you can try:
1) Manually editing the Xorg config file
2) Installing missing drivers
1) To edit the xorg config file, do this in a terminal:
sudo gedit /etc/X11/xorg.conf
and look for a section like:
To try the intel driver, change "vesa" to "i810" (or "intel", not sure which).
To add the HorizSync/VertRefresh info, find those values from some laptop documentation, then put them under the monitor section of the xorg file, e.g.:
VendorName "Monitor Vendor"
ModelName "Dell E193FP"
HorizSync 30.0 - 83.0
VertRefresh 56.0 - 76.0
Don't use the above values, those are for my monitor!
2) For 1) to work, you might have to install the Intel Graphics driver first, if it is missing. It'll be some "apt-get install ..." command (help anyone?). I think you can do "apt-cache search ..." for it, or something like that.
To test your changes you have to restart the X server. You can do that by simply rebooting, but sometimes the Ctrl+Alt+Backspace key combo does it, too.