[Zope] ZCatalog Update hangs Zope

Hi all When Updating the ZCatalog manually from the management interface Zope hangs itself up. Apache reaches the timeout and returns an error after 5 Minutes. Zope never comes back. After a restart all's fine again. I don't know whether ZCatalog did an update. Same thing happens when Cataloging the whole Site. (Zope 2.4.0 (Solaris)) I have manny "unable to uncatalogObject" errors in my Stupid.log. Regards Oliver Erlewein