I wouldn't recommend playing vanilla 1.0 - it's buggy beyond belief, to say the least. Random CTDs, disconnects, and a great deal more plague multiplayer games in it. The last official patch (1.4) is better, but still has a number of nagging issues.
The only thing required for most online games is use of the unofficial patches (current version is 1.497), which do a great deal to improve the game's overall stability and playability. A change log can be found at
http://www.giantswd.org/forum/viewtopic.php?t=1962 Good multiplayer games are a little rarer than they once were due to the game's age, however we still get good games going rather regularly.