samba - Mar 2002 - blanks in filenames can't be seen by Apple client...

We are using Samba to exchange documents between Windows (2000, XP and 98)
clients and one Apple Mac.
However, when we put files on the share containing blanks or special characters
(german umlaute), the Apple client either doesn't see them or isn't
allowed to
read them...
We (the Windows-clients) can see them with blanks and special characters in the
Windows Explorer.

Any idea what I could change to solve this ???

kr,
Joerg