This is the body of a dtml method <dtml-if language_id> <dtml-if "language_id=='2'"> <dtml-var ngo_contact_info_fr> <dtml-elif "language_id=='3'"> <dtml-var ngo_contact_info_es> <dtml-else> <dtml-var ngo_contact_info> </dtml-if> <dtml-else> <dtml-var ngo_contact_info> </dtml-if> The ngo_contact_info object is a dtml document that displays just fine when viewed on its own or called from a form If I call this method with language_id set to any value, I get the following error, every time: Error Type: ValueError Error Value: Invalid Header (0): Traceback (innermost last): File /home/sgendler/Zope-2.0.1-src/lib/python/ZPublisher/Publish.py, line 214, in publish_module File /home/sgendler/Zope-2.0.1-src/lib/python/ZPublisher/Publish.py, line 179, in publish File /home/sgendler/Zope-2.0.1-src/lib/python/Zope/__init__.py, line 201, in zpublisher_exception_hook (Object: ElementWithAttributes) File /home/sgendler/Zope-2.0.1-src/lib/python/ZPublisher/Publish.py, line 165, in publish File /home/sgendler/Zope-2.0.1-src/lib/python/ZPublisher/mapply.py, line 160, in mapply (Object: ContactInfo) File /home/sgendler/Zope-2.0.1-src/lib/python/ZPublisher/Publish.py, line 102, in call_object (Object: ContactInfo) File /home/sgendler/Zope-2.0.1-src/lib/python/OFS/DTMLMethod.py, line 156, in __call__ (Object: ContactInfo) File /home/sgendler/Zope-2.0.1-src/lib/python/OFS/DTMLMethod.py, line 370, in decapitate ValueError: (see above)