[Zope] Creating class instances brings up strange login dialog

[Andy Bulka]

Python script objects seem not to allow
 1. the creation of instances of my own custom classes e.g. Class AA:
 2. the use of __init__ constructor methods or anything starting with __

Restriction #1 is a rather extreme limitation that isn't mentioned clearly
anywhere in my reading, which includes the tutorials and the zope book.  The
zope book mentions only the security limitations and import library
limitations.  Why isn't the inability to create class instances mentioned?
Or am I running into a neewbee problem?

 Running the same python code as zope external methods works fine.

thanks for any help,
-Andy Bulka