Migration Plone3.3rc3 to Plone3.3rc4 failed

[bkeller]

With the following trace from a dry run:
    *   Dry run selected.
    * Starting the migration from version: 3.3rc3
    * Attempting to upgrade from: 3.3rc3
    * Upgrade aborted
    * Error type: exceptions.AttributeError
    * Error value: getCookedExpression
    * File "/home/zope/plone3/eggs/Plone-3.3rc4-py2.4.egg/Products/CMFPlone/MigrationTool.py", line 210, in upgrade newv, msgs = self._upgrade(newv)
    * File "/home/zope/plone3/eggs/Plone-3.3rc4-py2.4.egg/Products/CMFPlone/MigrationTool.py", line 321, in _upgrade res = function(self.aq_parent)
    * File "/home/zope/plone3/eggs/Plone-3.3rc4-py2.4.egg/Products/CMFPlone/migrations/v3_3/__init__.py", line 12, in three3_rc3_three3_rc4 cookCSSRegistries(portal)
    * File "/home/zope/plone3/eggs/Plone-3.3rc4-py2.4.egg/Products/CMFPlone/migrations/v3_3/__init__.py", line 25, in cookCSSRegistries resource.getCookedExpression()
    * End of upgrade path, migration has finished
    * The upgrade path did NOT reach current version
    * Migration has failed
    * Dry run selected, transaction aborted