Second Copy Troubleshooting
 

Long story short, I currently have two copies of Dominions 3 on my computer, having introduced an unpatched one to play in a demo-game with unpatched nations. Currently, it will run up until it tries to create a new game, then crash. I'm using a Mac OS X 10.6.8, and currently don't know how to fix it. That said, I have a few suspicions. So:
Does anyone know how to fix this?
Does anyone know how to create a second folder which contains map data, game data for individual games, etc. and get the two copies to each use one of these folders?

EDIT: There is a bypass currently, in which one simply uses a different user account. It's a bit clunky though, so alternate options are still useful.

Re: Second Copy Troubleshooting
 

I'm not sure if it works differently on Mac, but creating a second install on windows I just ran the installer and told it to install in a different folder (I went for c:\program files (x86)\dominions3unpatched rather than my main c:\program files (x86)\dominions3, obviously this will be different for you).

Provided you use the dom3.exe from your unpatched folder I would think it should work fine.