[Zope] Error appear in Python dos window.

Hi, my little Zope application works so far. But I just noticed, that some errors appear in the python dos window. Sometimes I get the following Errors: -Catalog uncatalogObject unsuccessfully attempted to uncatalog an object with a uid of /NewsFolder/NewsItems/N_1 -UnTextIndex unindex_object tried to unindex nonexistent document 0 Perhabs someone knows more aboute these errors. I think, that I didn't attemtpt to uncatalog an object. How could I? Thank you, Marc