The default resource bundles for the SSO portlets are missing some entries, hence the ResourceBundle exception if using a locale like nl, fr...
(SSODetailsResources.properties and SSOResources.properties in applications/j2-admin/src/java/org/apache/jetspeed/portlets/security/resources)
The files should be identical to the _en version.
I found the problem in branch 2.0.1 and checked the head to be sure.
Note: this is probably related to the SVN comment regarding 'lost files'.