Maybe the Intel open source driver still is not able to support higher resolutions?
There is some info here
If I had such problems, I'd try to edit my xorg.conf file
but as you may now from Jaunty it is not available by default under
Another question : Is your system up-to-date? Intel driver is officially maintained in Ubuntu,so if any bugs appear fix are released in the updates.
You may also try to use xrandr command to manually put the desired resolution
Last thing: Check if you have this package installed
, if not, install it.