I had the same problem with an Intel 82945G, and *thought* I had posted a decent
fix here. But, either my memory is faulty, or Yahoo! "Message Search" is
faulty...

Try booting with the "nomodeset" option. To do this at boot time (as a test):

Hit the letter "e" when the Grub boot menu displays. You'll get a simple editor
window.

Use the arrow keys to move the cursor to the end of the line that shows "quiet
splash". add the string "nomodeset" to the end.

Old: .....quiet splash
New: .....quiet splash nomodeset

Now, hit CTRL-X to continue your boot. You should find a greater range of
available screen resolutions when you log in.

If it works, post back here. To make it permanent, you'll have to edit a Grub
configuration file, and the process is different for Grub 1 vs. Grub 2.