When trying to setup automatic builds based on commits in CVS using the
automatic build URL of
http://YOURHOST/hudson/job/PROJECTNAME/build?token=YOUR_TOKEN_HERE

This returns a 404 error unless you use it in the browser that your already
logged into hudson (presumably your Session overrides the need for the token).

The security model I am using is the matrix based system with the users and
passwords living in LDAP (openLDAP in this case).