[Zope] dtml-call fails silently, bug or feature...

Coming back for maintenance to a DTML site and noticed something strange... <dtml-var standard_html_header> <dtml-call somethingThatDoesntExist> <dtml-var standard_html_footer> ...fails silently and does nothing ! I mean there is no AttributeError or such exception saying that there's no "somethingThatDoesntExist" object. Is it a bug or a feature ? Noticed in a Zope 2.3.3 and tested (with the same result) with Zope 2.6.1 Thanks in advance. --Gilles