Out of nowhere, my 24" mon won't recognize 1920x1200...wtf?

[teddyFBI]

I use a 24" external monitor hooked up to my laptop to create a gigantic desktop, and I've had no problem running the monitor at 1920x1200 for the last year or so.

I get back from traveling today, however, and for some reason, in the right-click...properties...settings window, and the "Screen Resolution" scrollbar only goes up to 1024x768.

What gives?? I've tried everything I can think of, including multiple re-starts and I can't for the life of me get it to "recognize" that the 24" monitor is capable of resolutions up to 1920x1200. I've never had this problem before. Usually, all I do is plug in the external monitor's cable into the VGA port in the back of the laptop, and it immediately recognizes that it can do up to 1900x1200, but this time it won't.

Help!