[Zope] Products breaking other Products?

[James W. Howe]

I just encountered a problem which scares me to some extent.  I have 
developed my own product with my own set of ZClasses.  In my Products 
folder I had my product, some other products and the PTKBase product.  The 
version of the PTK was from a couple of weeks ago (or so).  Yesterday I 
retrieved the latest PTK stuff from the CVS repository and updated the 
contents of my products directory with this version of PTK.  Suddenly 
existing instances of ZClasses that I had created previously, were 
appearing as broken.  They apparently couldn't find their product.  I was 
confused by this, because I was able to add new instances of my 
ZClasses.  After posting a message to the zope mailing list, I received a 
reply which suggested that perhaps a product unrelated to my product was 
causing a problem.  Having nothing else to lose, I replaced my PTKBase with 
the old version of PTKBase.  After restarting Zope my broken ZClasses were 
once again functioning.

My question is this, why should a product unrelated to my product cause 
problems with my ZClasses?  I feel a bit uncomfortable with the notion that 
one product can seemingly affect another.  I don't believe any of my code 
relied on anything relating to the PTK.  Can someone explain what might 
have happened?

Thanks.

James W. Howe				mailto:jwh@allencreek.com
Allen Creek Software, Inc.		pgpkey: http://ic.net/~jwh/pgpkey.html		
Ann Arbor, MI  48103