Simple j_security_check example not working

Posted this on the tomcat-user list with no replies so lets try here!
Hi Guys
Here (link to src) is a simple example of form based login I'm trying to get working on Tomcat 4.0.3 and it doesn't!!! I've checked the archives and noticed
someone else had the same problem and never got past it! Anyway if you type the url
http://localhost:8080/SCJWD/
And click on the Secret Servlet, you get re-directed to the form based login page and if you type in the correct username and password (tomcat, tomcat, by default allowed for tomcat-4.0.3) you get an error - and I quote
type Status report
message Invalid direct reference to form login page
description The request sent by the client was syntactically incorrect
(Invalid direct reference to form login page).
Am I missing something somewhere .. Because I copied this example straight out of the java servlets book - jason hunter.
If you use incorrect credentials then the behaviour is as expected, ie you get redirected to the error page.
Can some one shed light on what I might be doing wrong?
Cheers
Jas

bump and :-
Replying to my own message ..
http://nagoya.apache.org/bugzilla/show_bug.cgi?id=8976
Don't know if it applies in my situation ..
Jas