Jira 2.6.1 throws a ClassNotFoundException on initialisation when deployed in JBoss.

11:25:12,421 DEBUG [com.opensymphony.user.UserManager] loading using config : osuser.xml
11:25:12,436 DEBUG [com.opensymphony.user.util.ConfigLoader] Loading config
11:25:12,457 DEBUG [com.opensymphony.user.util.ConfigLoader] Authenticator class = com.opensymphony.module.user.authenticator.SmartAuthenticator {}
11:25:12,479 ERROR [com.opensymphony.user.util.ConfigLoader] Could not create instance of authenticator
java.lang.ClassNotFoundException: No ClassLoaders found for: com.opensymphony.module.user.authenticator.SmartAuthenticator
at org.jboss.mx.loading.LoadMgr3.beginLoadTask(LoadMgr3.java:161)
at org.jboss.mx.loading.UnifiedClassLoader3.loadClassImpl(UnifiedClassLoader3.java:169)
at org.jboss.mx.loading.UnifiedClassLoader3.loadClass(UnifiedClassLoader3.java:123)
at java.lang.ClassLoader.loadClass(ClassLoader.java:255)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:315)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:140)
at com.opensymphony.user.util.ConfigLoader.addAuthenticator(ConfigLoader.java:88)
at com.opensymphony.user.util.ConfigLoader.access$200(ConfigLoader.java:37)
at com.opensymphony.user.util.ConfigLoader$ConfigHandler.endElement(ConfigLoader.java:158)

The com.opensymphony.user.util.ConfigLoader does not check for ClassNotFoundException but does check for NoClassDefFoundError. This has been fixed in the current CVS version of OSUser.