[Zope] standard_error_message behavior

[Stephen Pitts]

Why is standard_error_message called only sometimes? I've overridden
standard_error_message on my site to print "Mysterious Error has
Occurrred" and email me. 

It works when I call one of my DTML methods that requires parameters
without parameters, i.e.
http://www.centralchurchyouth.org:8100/search?
invokes standard_error_message OK because the keywords parameter is not
specified

However, on a simple notFoundError, standard_error_message isn't
invoked, i.e.
http;//www.centralchurchyouth.org:8100/page_that_does_not_exist
shows a standard Zope error screen.

Is this supposed to be this way? If not, how can I make my
standard_error_message be used in all situations?
-- 
Stephen Pitts
smpitts@midsouth.rr.com