[Zope] Problems moving Product to Zope 2.1 site.

[Jay, Dylan]

I have a ZClass based product on a Zope 2.0.1 site. I wanted to put this in
an new Zope 2.1 site however I'm having problems. I've tried exporting the
Product and then importing in into the Control_Panel of the new site. If its
in xml format I get the following error
<!--
 Error type:  TypeError
 Error value: ('not enough arguments; expected 2, got 1', <extension class
ZClasses.Method.MW at 009E4330>, ())
 -->
<p><a href="http://www.zope.org/Credits"><img
src="http://cornfed.auslabs.lucent.com/p_/ZopeButton" width="115"
height="50" border="0" alt="Powered by Zope"></a></p>
</BODY></HTML>
<PRE>
Traceback (innermost last):
  File D:\Program Files\Zope2\lib\python\ZPublisher\Publish.py, line 214, in
publish_module
  File D:\Program Files\Zope2\lib\python\ZPublisher\Publish.py, line 179, in
publish
  File D:\Program Files\Zope2\lib\python\Zope\__init__.py, line 201, in
zpublisher_exception_hook
    (Object: ElementWithAttributes)
  File D:\Program Files\Zope2\lib\python\ZPublisher\Publish.py, line 165, in
publish
  File D:\Program Files\Zope2\lib\python\ZPublisher\mapply.py, line 160, in
mapply
    (Object: manage_importObject)
  File D:\Program Files\Zope2\lib\python\ZPublisher\Publish.py, line 102, in
call_object
    (Object: manage_importObject)
  File D:\PROGRA~1\Zope2\lib\python\OFS\ObjectManager.py, line 478, in
manage_importObject
    (Object: ElementWithAttributes)
  File D:\Program Files\Zope2\lib\python\ZODB\ExportImport.py, line 216, in
importFile
  File D:\Program Files\Zope2\lib\python\ZODB\ExportImport.py, line 318, in
importXML
  File D:\Program Files\Zope2\lib\python\ZODB\ExportImport.py, line 283, in
importFile
TypeError: (see above)

If its a zexp, I get an error saying that my ZClass does not support the
copy operation.
Is this 2.1 incompatibility problem or am I doing something wrong?