SimplePortlet crashes Zope when updating schema

When updating the SimplePortlet archetypes schema in
the archetypes tool, zope crashes very ungracefully
with this error:
Unhandled exception in python.exe
(COMPUTEDATTRIBUTE.PYD): 0xC0000005:Access Violation

To reproduce, create a fresh zope instance, add a plone
site, install archetypes and SimplePortlet in the
quickinstaller. Add a Plone site.
Login to the plone site, create a portlet.
Go back to the zmi, archetypes tool, refresh only the
SimplePortlet schema (all objects).
Result: Crash.

Apparently it has something to do with this line:
schema['topic'].vocabulary =
ComputedAttribute(getTopics, 1)

I'm running windows XP SP2,
Zope 2.7.3-0, python 2.3.4

and the following:
Listing versions of c:\Zope273\instance5\Products
Archetypes 1.3.1-final
BTreeFolder2 BTreeFolder2-1.0.1
CMFActionIcons 0.9
CMFCalendar CMF-1.4.7
CMFCore CMF-1.4.7
CMFDefault CMF-1.4.7
CMFFormController 1.0.4
CMFPlone 2.0.5
CMFQuickInstallerTool 1.5.1
CMFTopic CMF-1.4.7
DCWorkflow CMF-1.4.7
Epoz 0.8.6
ExternalEditor 0.8
Formulator Formulator 1.6.2
GroupUserFolder 2.0.1
MimetypesRegistry 1.3.2-7
PlacelessTranslationService 1.2-rc1 (CVS/Unreleased)
PloneErrorReporting 0.11
PortalTransforms 1.3.2-7
SimplePortlet 1.0beta1
generator 1.3.0-11
validation 1.3.0-11

Thanks for a promising - and simple! - product,
if you need more info contact me.
Sune Woeller