Seik,
I am sorry but your email was sorted out as junk by Hotmail. I had to go and find it in the junk email folder when I saw your posting

There must be something weird about it
To start a multiplayer game you need to save your game in a shared folder, different form your local savegame folder. The helper will copy your turn files into your local savegame folder and then back to the host (sahred folder) automatically. I am sorry the error message is somewhat confusing

, it simply cannot copy a file onto itself and thinks there is a problem accessing it.
So -- when creating a game, save it in a different folder. Give it a try, that should work -- I used it today to play
BTW I recently updated the app - it works on both Win2K and Win9x now. There was a nasty incompatibility bug
Hope this helps -- Aub