[Zope] problem saving file twice with ange-ftp

[John Hunter]

I am using ange-ftp under GNU-emacs to edit my Zwiki Web in
emacs-wiki-mode and am encountering a strange problem.  If I edit a
page, I can save the changes *one time only*.  After that, I get an
error 426 from the ftp server:

Opening output file: FTP Error: "426 Error creating file.", /jdh2358@nitace.bsd.uchicago.edu 8021:/Wikis/April/FrontPage
Mark set [2 times]

If I kill the buffer and reload it, I can again make changes to it 1
time, and get the error after subsequent save attempts.

Any suggestions?  Is this a version objects problem?

Thanks,
John Hunter 

Version info:
Zope-2.3.0
python 1.5.2
GNU emacs 20.7.1