Windows Mode Resolution issue?

[hyzon]

On my desktop, I'm having a bit of a strange issue:

Comp specs:

Nvidia Geforce 9800 GTX+
Windows XP SP3
(Does anything else matter?)

I can run fullscreen at 1680 x 1050, but when I try to run in windows mode it will only run at 640 x 480, and that's even the only option available when I check video modes.

Few other quirky things, when I run in fullscreen, after I alt tab back and forth, the mouse point works, but is the desktop native pointer, not the ingame yellow decorative one?

I've updated drivers, and tried tweaking a few settings, but at this point I'm at a bit of a loss. Thanks for reading!