[Zope] Problem with Zope and Proxy server

[Duncan Booth]

I do most of my network access through a firewall with a Netscape 
Suitespot Proxy server and I now have a Zope 2.0 Beta 3 system set 
up outside the firewall. Mostly it works fine, but I find that attempting 
to submit a form with a POST method always fails with Error 400 
(Not Found). This happens with any form I create but only if I use 
POST (changing the submit method to GET and it all works fine) and 
only if I access Zope via the proxy.

The problem seems to be with the Netscape Proxy server 
interpreting the result from Zope as any side-effects on the Zope 
server do happen.

Can anyone suggest what is happening here?