[Zope] socket problem

When I try to start Z Server i get the following error messages: File "/WWW/Docs/product_development/teams/AMD_framework/dev/Zope/ZServer/medusa/asyncore.py", line 205, in bind return self.socket.bind (addr) socket.error: (98, 'Address already in use') I don't use the number 98 in any address or port (http=80, ftp='' and monitor='') so what could this error be about ?