Well guys (thanks for thinking along with me) I went for NTFS and got involved with crazy other problems (folder doesn't excist etc.). Got to impatience to cope with all that, whatever caused it, and went for ext3 which instantly did the trick (why? I will probably never know!). So, solved partly for my sharing Windows-lovers-friends has to excuse me this time
Selfish spoken: My problem is solved (although I still don't grasp the "in's and out's).