Anyone know anything about using duel monitors?

[Kadana Sorano]

First, I apologize if this is the wrong place, but as it isn't Secundi related i didn't think it would go in the Library..

OK, so A while back I paid quite a lot to someone to build me a shuttle comp, and hook it up.  He set it up with my old desk top cop, so that I have duel monitors, and the comps are connected via a hmm kswitch?  

Anyway, the left monitor was my main, and the right my secondary.  Left being the flat screen, and right being the older boxy one.  When you right click the monitor, and click properties, settings, it shows pictures of two monitors side by side.  The left monitor has a number 1, and the right a number 2.  When doing things on my comp, I can drag stuff from the left monitor, to the right onto the right monitor.

Well, that's how it worked then anyway...  But as some of you know from all my whining, my shuttle was down and in the shop.  I just got it back yesterday, but when I reconnected everything, the monitors were all screwy.

When I tried to drag things from the left monitor, to the right onto the right monitor, I couldn't.  I had to instead drag them form the left monitor, to the LEFT, which then brought them up on the extreme right of the right monitor.  Usable, but very aggravating and disorientating.

So I spent the night and morning fiddling, trying to "fix" it, and discovered that if I go into the properties/settings of the monitors, and click "Identify" it tells me my flat screen is my number 2 monitor, and the boxy one is my number 1 monitor.  

I disconnected the cables, rebooted, fiddled, and somehow (I'm not sure how) "fixed" it.  So now I can once again drag things off of the flat screen to the right onto the right monitor.  But.. not knowing HOW I "fixed" it, I went back into the monitor settings.. and low and behold, the pictures of the monitors are now switched, with a number 2 on the left image, a number 1 on the right image, and clicking identify still tells me the flat screen is my number 2 monitor.

Now, I know its "working" and I should probably let it be, but it frustrates me because its not how it was (how it belongs?) and I want it "fixed" for real.

So.. if I haven't put you to sleep, or confused the hell out of you yet, any idea how I can "fix" this properly?