[Zope] debug info

[John Hunter]

I am having a problem with roles and permissions.  I find that I
cannot access some pages on my site unless I have the role Manager,
although I have tried to customize the roles and permissions so that
other roles can access this content.  Actually, this used to be
working and now it is no longer working and I'm trying to figure out
what has changed.

When I try and access the protected content, I am prompted for a user
name and passwd.  If I enter a user who does not have the Manager
role, I get the error

  You are not authorized to access this resource.
  Username and password are not correct. 

If I add the Manager role for that user, however, I can then access
the content.

The site is built as a python Product, and I am using
ClassSecurityInfo to manage my permissions and roles for the various
methods.  

My question is: is there any way I can get better diagnostic
information for debugging, for example what resource I am trying to
acquire that I don't have permission for?  I've checked the Z2.log but
there is no helpful information there.

On a related note, is there any way to get zope to give full
tracebacks rather than the limited tracebacks it supplies by default?

Thanks,
John Hunter

zope 2.7