Game crashes when starting multiplayer

[spet]

Hey people.
When I play multiplayer sometimes the game crashes (doesn't freeze). It happens when I join a game and i'm asked for a password for my civilization. then I click OK and the games just crashes...
It doesn't happen all the time, but most of the time it is.

I have updated my graphic card (radeon xpress 200).

What should I do?

Thanks.

 

[spet]

Ok, the problem is that the game crashes when it's 1230 AD.
I can play games without problem till 1230AD, then, if I try to join, it crashes.