I recently installed the ToB add-on, but I have a friend who has not. Can we still play a regular multi-player SoA game together?

No, I'm afraid you can't. In order to play multi you need to have the exact same game, without any add-ons or patches that the other player doesn't have.
So eithre you need to deinstall TOB or your friend needs to buy it http://www.tgeweb.com/cgi-bin/ubb/no...iles/smile.gif
Good luck!

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