I found this solution mybookworld.wikidot.com/fix-samba-for-mac-osx-lion
but on my MB World (Blue Ring) there is no file mDNSResponder.conf in /etc
There is a mDNS.sh in /etc/init.d, but I don't know where its configuration file resides.
I did hack my MB World according to these tutorials: kyyhkynen.net/stuff/mybook/index.php
My MB World is running the original samba-version that shipped with it. I don't intend to upgrade samba.
OSX Lion tells me, I don't have the neccessary rights to access the network ressource (-> my share).