This is actually a question that crosses 3-ish topics, so I didn't know where to post it. Mods please move if there's a better place suited for the question:

I have a 15" laptop running a ATI Radeon x1600 MOBILITY. I recently bought a 22" monitor that I hooked up to the laptop, and switched the 22" LCD to be my primary display. I am able to change the windows resolution to 1680x1050, but any game that I play has only the max resolution of 1280x800 showing up, even though my new monitor is capable of 1680x1050. Anyone know how to make this higher resolution show up?

^ Which game is it? Some games do not support high resolutions such as Diablo 2...

I'm 101% certain that the games I'm trying support 1680x1050. One example is Sins of a Solar Empire, which I think supports any resolution that your card/monitor can run -- but for me it's locked at 1280x800 as the max.

I'm about 101% certain it is the driver that is limiting your resolution. It is a custom driver for your laptop. Try an unofficial driver or update you driver and see if that works.

Unofficial drivers are your best bet.

1400x900...........................

you could always try to modify the config.ini file for the game you are trying to run.

make sure all of your drivers are up-to-date, as far as the graphic chipset goes. try driver magician it work great. its a $29.95 investment you wont regret.

The problem is not in your games but in graphic card
It does not support resolutions higher than 1280X800