Where does Ubuntu 11.10 keep its display settings?

If you hadn't specified your display settings explicitly, they are not saved to any config file.
Xorg tries to choose the best mode automatically.

Thanks Bob, I was afraid of that. My concern is that the 'Displays' config option lists just 2 resolutions (max of 1024x768) and cannot detect my Monitor type. I have an nvidia card, so I can use the nVidia app. This correctly identifies my monitor (Philips 192E) and it's appropriate resolutions.
Now, to complicate things, before I applied the nvidia driver to my system, Displays COULD detect everything correctly. So, perhaps it is the nVidia driver that causes issues. But, when I remove those drivers (Additional Hardware) it doesn't help the situation. Displays still shows the limited options. So, with the driver removed, Ubuntu still can't detect the right settings.
This wouldn't be an issue except that when I reboot, the nVidia Config's settings are lost and I have to go in and reset them.

Can you tell me where to find good, current Xorg information so I can try to troubleshoot this?

Thanks

https://help.ubuntu.com/community/BinaryDriverHowto/Nvidia

You can also try nouveau which is getting better these days.
https://wiki.ubuntu.com/X/Troubleshooting/NvidiaDriverSwitching

https://wiki.ubuntu.com/X/Debugging
http://wiki.x.org/wiki/

Thanks Sam. I read the Binary Driver for nVidia article already. Good information to know, but nothing to help me here. However, I will try your other suggestions. I'm new to Ubuntu (semi-new to Linux in general), so any information is good information. I'll have a look and report back if I get it sorted.
Thank you both.

Okay, so I removed nVidia and installed Nouveau, but the reboot led to no X. I checked /var/log/Xorg.0.log and saw it just tried to load the nVidia drivers and failed to find them (obviously). I had previously edited the /etc/X11/Xorg.conf file with the nVidia settings app, so I removed that file and replaced with a vanilla one. I rebooted and it looks like I'm good again. So, it looks like Xorg.conf is used, but probably shouldn't be. :)
Thanks for all of your help everyone.

Actually there is no xorg.conf since, not sure, was it Lucid?.
Proprietary driver create one and sometimes users implementing specifics.
https://wiki.ubuntu.com/X/Config

Yes, the nVidia driver had created one, so even though I'd removed the driver and installed Nouveau, X wouldn't start as it was still looking for nVidia (as specified in xorg). Once I removed the file and rebooted X came back up.
Thanks again.
The problem was that every time I googled for help it talked about Xorg.conf and editing it. No where could I find that Ubuntu automatically did all this on the fly, so I was lost. Thanks to you and Ben for helping me figure it out.

No matter what driver you are using, you can still force some display mode manually via xorg.conf config file or with xrandr utility.
https://wiki.ubuntu.com/X/Config/Resolution

Thank you Bob.