[Zope] Exception raised adding date

Hi, I try adding a Property of type "date", with no supplied value, to a Folder and get the following Exception. Bug? mark Exception Type AttributeError Exception Value SyntaxError instance has no attribute 'replace' Traceback (innermost last): * Module ZPublisher.Publish, line 101, in publish * Module ZPublisher.mapply, line 88, in mapply * Module ZPublisher.Publish, line 39, in call_object * Module OFS.PropertyManager, line 253, in manage_addProperty * Module ZPublisher.Converters, line 108, in field2date * Module cgi, line 1033, in escape AttributeError: SyntaxError instance has no attribute 'replace' REQUEST form submit ' Add ' type 'date' id 'sdfsdfdfsdf' value u''