[Zope] problem with ZUBB / no topic set

Hello, after installing ZUBB (ZDiscussions 0.6. right?) everything works fine with the single exception that the topic of no message gets set. That means, after posting, all messages show "(no subject)". The message preview HTML source still shows the correct value in the hidden input form tag named "title". Could the problem be a clash between the "title" form entry and the title of another Zope object? I am using ZDiscussions-0.6 and Zope 2.3.0. thanks --Oliver