[Zope] problems with ftp and 2.3.0

[Oliver Frommel]

Hello,

there seems to be a problem with FTP in Zope 2.3.0 (on Linux Redhat 6.0).
I can list the contents of the root dir (however the Zope console shows
an error "PROBLEM(100) ZServer unhandled connect event").
If I want to change to certain subdirs I get "550 No such directory", if I try
to list their contents the error message is "550 Could not list directory".
These subdirs are just regular Folders but one of them contains custom ZClass 
instances while the other contains DTML Documents/Methods, Images, External
Methods, a User DB, a Catalog, a MailHost and a MySQL DB Conn and a LocalFS
(already patched) so i guess it _should_ be listable, right?
Of course both Folders are listable in the HTML management interface.
Other Folders in the root dir are listable too.

Any idea what's wrong or how to debug the problem?

Thanks
--Oliver