Funny you should say this!
I was messing around with external monitors, and while I was hooked up to one of them, I decided to press the "mirror" box in the display prefs. Boy, was that a mistake! Got what you are talking about. And since I can't make out the display on either screen now, that monitor config. is shot. Others work (I have an office filled with all kinds of monitors), but I can't figure out how to reset that particular resolution set back to spanned.
I've read that you can reset the P-ram of a mac, but I tried that on the dell with no results.
So, I'm looking for a way to wipe display configurations without killing the original presets. (I guess).
I really know nothing about the mac environment. This is my first foray.
Dell mini 9 (white)
Self installed bluetooth service unit
Self installed Super Talent 32GB SSD OSX 10.5.6
Primary apps at the moment: Office, Firefox, Evernote.