Exeption access violation

[Waltari]

I bought this game from steam when the great offer arrived and so did some of my friends and I really like the game so far. The problem is that the game randomly crashes during online gaming. It just moves to desktop and shows me these error messages.

http://i86.photobucket.com/albums/k9...g?t=1248888695

Its getting really annoying since it does it every second game or so and its pretty lame when my friends finally have time to play the game online and I just keep crashing . We have also played lots of coop missions and they have worked just fine. I am running on a Vista 64-bit, but ive heard that it works fine for some people on it so I dunno if it really matters.

Any help would be appreciated.