Error-page directive does nothing

[pete . storey]

Hi,
we have a lot of occasions where I use the directive

  <error-page>
    <error-code>500</error-code>
    <location>/errorPages/500x.jsp</location>
  </error-page>

in a web.xml file but it does nothing, particularly for errors thrown by a 
servlet.  I have upgraded now to Tomcat 4.1.27 as I have seen some 
problems with this before but does anyone have any ideas?
cheers
Pete