Problem with the OAI pack

Hello

I got stuck with the OAI pack. I've installed all resources (oaipmh, OAICore and SilvaOAI). Then I added a "OAIPMH Service" to the Zope root (using http://oai.ethz.ch/oai.asp as base url). On the edit tab of this service, I got oai_dc and oai_dc_1.1 displayed as supported metadataformats. However, if I check them and click 'Change Settings', I get the following error:

Error Type: AttributeError
Error Value: BTreeFolder2

Traceback (innermost last):
  Module ZPublisher.Publish, line 101, in publish
  Module ZPublisher.mapply, line 88, in mapply
  Module ZPublisher.Publish, line 39, in call_object
  Module Products.OAICore.core, line 67, in manage_edit
  Module Products.OAICore.core, line 215, in createStorage
  Module App.FactoryDispatcher, line 26, in __getitem__
  Module App.FactoryDispatcher, line 29, in __bobo_traverse__
  Module App.Product, line 67, in _product
AttributeError: BTreeFolder2

I can set up and update a catalog without a storage checked. However, when I then add a "Silva OAI Query", I get an empty list of metadata formats. Consequently, I get a render error if I preview the query.

Did I miss something?

I'm using Silva 1.2 on Zope 2.7.4-0, python 2.3.4. The OAI pack parts are oaipmh-1.0.1, OAICore-1.0.3 and SilvaOAI-1.0.2.

Regards
Benno