Hi Maur!
Are you hosting or joining? If you are joining, try using a zip file of the savegame from whoever hosted sent via AIM, ICQ or e mail prior to restarting your game. You will find it is infinitely faster (particularly if you have a number of players and you have narrow-band connections), and probably a lot smoother when you load up. If you're hosting, I have never seen that problem and would like to hear more, although Stefan or someone else might know what it is right off.
Hope this helps!
Play On!