Bundles that contain EJBs deadlock on "stopping" when the bundle is restarted for an update. Glassfish has to be killed (shutdown doesn't work) and the bundle cache cleaned to resolve the issue.
Probably not related, but the update is triggered by DeploymentAdmin (Apache ACE). Other bundles (non-ejb) work without problem.
The attached bundle is an example of a bundle that always hangs when updated.