...as soon as I contact a civilization, or sometime there after when in trade or diplomacy talks, the game will freeze. It is only when another civilization talks to me and the leader pops up and talks to me.
I had virtually the same problem (instant reboot/blue screen when AI civs would talk to me) and after trying lots of different things (some of which would work for a couple times) I finally seem to have fixed it permanently.
What I did was turn down all the graphics options to low and turned of AA. Game looks virtually the same and hasn't crashed in over an hour since doing this *crosses fingers*. I'll take stability over looks, heh.
FYI, I had played two games before this without encountering this problem, so I don't know why it suddenly came up in this game. Maybe because this one is larger with more AI civs (7)?
Hope this helps you.