Unable to uninstall Singing and Dancing (0.9.9).

[richard]

Unable to uninstall Singing and Dancing (0.9.9).
Traceback (innermost last):

* Module ZPublisher.Publish, line 237, in publish_module_standard
* Module ZPublisher.Publish, line 179, in publish
* Module zope.event, line 31, in notify
* Module zope.component.event, line 24, in dispatch
* Module zope.component._api, line 136, in subscribers
* Module zope.component.registry, line 321, in subscribers
* Module zope.interface.adapter, line 585, in subscribers
* Module plone.transformchain.zpublisher, line 113, in
applyTransformOnFailure
* Module plone.transformchain.zpublisher, line 79, in
applyTransformOnSuccess
* Module plone.transformchain.zpublisher, line 55, in
applyTransform
* Module zope.component._api, line 172, in queryUtility
* Module zope.component.registry, line 163, in queryUtility
* Module ZODB.Connection, line 860, in setstate
* Module ZODB.Connection, line 914, in _setstate
* Module ZODB.serialize, line 612, in setGhostState
* Module ZODB.serialize, line 605, in getState
* Module copy_reg, line 48, in _reconstructor

TypeError: ('object.__new__(Salt) is not safe, use
Persistence.Persistent.__new__()', <function _reconstructor at
0xb7701d84>, (<class 'collective.dancing.channel.Salt'>, <type
'object'>, None))

Version Overview
* Plone 4.1.2 (4111)
* CMF 2.2.4
* Zope 2.13.10
* Python 2.6.7 (r267:88850, Sep 9 2011, 10:45:15) [GCC 4.4.3