[Zope] Authentication problem when accessing ZSQL method

Hi, I am experiencing great frustration when trying to implement a drop-down list based upon one of the how-tos I found on the Zope site. Whenever I try to 'view' the DTML method which references the ZSQL method, I am prompted to authenticate by my browser. I can't see anything in the security attributes for the SQL method which requires authentication, and I can 'test' the ZSQL method succesfully without requiring authentication. I have tried providing my user credentials (ie, to match the one and only user defined in the 'acl-users' list', but that fails. Where should I start looking for the answer? Regards Steve Smith