[Zope] ERROR Zope.ZCatalog reindexIndex could not resolve an object from the uid

Hi all, I'm facing some trouble with a Plone Site. When trying to insert a new page I get an error complaining about some lost uid. I have tryied clearing uid_catalog's indexes: UID, id, and Title. Then I reindex those indexes, and in the event.log I got several errors: ERROR Zope.ZCatalog reindexIndex could not resolve an object from the uid '/path/to/the/object' Does anyone knows how to troubleshoot this? Thanks in advance, Manuel.