Couldn't fix the problem, messed around with ownership etc in windows, nothing I did came trough (kept getting errors that I couldn't edit things). Solved it by deleting and creating the shares again. Thanks for all the help guys, I hope I won't be bothering you again :)
One thing I noticed trying to solve this problem: I think there is something wrong with the help page of "Disk Setup" tab "Setup". I see all this html-stuff (<�!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <�html lang="en-us"><�head> etc)