[Zope] ZClass export/import vs Distribution package

[Dominique.Dutoit@cec.eu.int]

I got some serious problems when trying to import an exported ZClass. I have
enhanced a ZClass by editing some part of the propertysheets and moving
around some methods. I though that the most straight way was to import the
ZClass from my development server to the production server.

- But when I tried to edit an previously created object depending on my
ZClass, I get the old behaviour of my ZClass.

- When I tried to restart the production server, I got corrupted data in the
products folder.

I gave it up and restored my backup. Today, I have tried to make a
distribution package and I put it in the lib/python/products folder of my
production server. I deleted the previous version of my ZClass through the
Control Panel and I restarted Zope. And then everything goes right.

So, is it definitly better to work with distribution package of ZClass
instead of importing the same ZClass?