[Zope] Authentication problems with Zfile

[Sherman Lambert]

I have an intranet that has been running for several years.  Last summer I
upgraded to zope 2.6.1.  I have recently had users having trouble accessing
some Zclass objects (for viewing).  For some reason zope is requesting
authentication (pop's up the username and password request).  As best as I
can tell it will not take any username (w/ password), and authenticate it.
BUT...  if the user cancels the authentication dialog, the everything
proceeds as normal (like expected before the authentication dialog poped
up).

All of the Zclasses in which this probem arises have a base class of ZFile.
I created a ZFile object, and it to exhibits this problem.

I am confused.  Shouldn't zope toss me to a "tried to access an unauthorized
object" page?

Using the error log I have found that the user is requesting
//zope_path/ZFile_object/LOCK.  It seems resonable that the LOCK (method?)
is causing the problem.  Is there some way to make the object call not use
LOCK?

Has anyone had a simular problem?  Any suggestions?

TIA
Sherman