CodeGenerationException mocking a class in Eclipse plugin

When attempting to mock a class in an Eclipse test plugin (a plugin that tests another plugin), a CodeGenerationException is generated when running under OSGi classloaders (the Run As | JUnit Plugin Test).

This is similar to the bug ID: 2759024, but not quite the same.

There are long descriptions of how JMock solved it: http://jira.codehaus.org/browse/JMOCK-124
and Mockito solved the same issue: http://code.google.com/p/mockito/issues/detail?id=11&can=1

The last comment in the Mockito issue ( http://code.google.com/p/mockito/issues/detail?id=11&can=1#c29 ) looks to be the key to a solution. All about taking care which classloader cglib uses,