Spaces visible in panel even if view right not set

Hello all, a few months ago, there was a brief discussion of a similar issue: http://mail-archive.objectweb.org/xwiki-users/2006-02/msg00102.html now i am facing a different problem, which might be related to that. when you add a new space, xwiki asks you to enter a title (the title of the introductory space page) and a text that describes that space. save and view works fine, it automatically appears in the right side panel. now, if you set appropriate rights to that space, acces to pages belonging to that space is secured via the xwiki built-in authorisation. the space itself, however, is still visible in the right hand panel. and if unauthorized user click on it, they see an unresolved velocity fragment in the panel. how can i influence that behaviour? i think, user should not see spaces, that they cannot access in the end, as it blows up the navigation panel on the right hand. Yours Thomas Kr�mer