Succinctly:
24-bit+Nvidia=Screen garbled
16-bit+Nvidia=Screen good, mouse cursor invisible

Detailed info:
When I launch the X server in 24-bit mode with the Nvidia drivers (tried both 71.76 and 76.76 version), my screen is garbled and it seems like they are overlapping.

When I launch the X server in 16-bit mode with the Nvidia drivers (both the 71.76 and 76.76), my screen is fine and dandy, BUT, the is mouse cursor icon is invisible. I can "see" my mouse moving around because the icons and KDE taskbar are highlighting up and the little mini-icon is bouncing around the invisible mouse cursor.

I've tried 24-bit with all different resolutions. 1280x1024, 1024x768, 800x600... they all turn the screen garbled. So the 24-bit thing doesn't work with any resolution.

My specs:
Nvidia 6600GT
Samsung Syncmaster 930B (analog cable)

So does anybody have any ideas on what is going on? Do you think it would make a difference if I got a DVI cable?

This problem has plagued me with different distros. Mandriva 2006RC2, Kubuntu, Debian, and now SuSE 9.3.

I fixed my problem! Hope this helps other people.

Turns out that in my /etc/X11/xorg.conf file, I had to change my video driver from "nv" to "nvidia" and give the BoardName "GeForce 6600GT". I guess running /etc/X11/xorgconfig and selecting "Nvidia GeForce" points it to the wrong driver ("nv") rather than "nvidia", the correct one. Once I made those changes, the Nvidia logo appeared and I am now able to see my mouse cursor AND boot in 24-bit depth mode.

Well of course xorgconfig wouldn't support a proprietary driver like nvidia

The board name is irrelevant, it's just there to help you keep them straight if you had two graphics cards and can be anything you want.