JBossResourceException when Admin Console within JBoss EAP tests Datasource Connection

Issue

Using a datasource with an encrypted password an exception similar to the following is logged as the connection is tested: -

MySQL

2010-09-30 11:24:28,222 WARN  [org.jboss.resource.connectionmanager.JBossManagedConnectionPool] (ResourceContainer.invoker.nonDaemon-1) Throwable while attempting to get a new connection: null
org.jboss.resource.JBossResourceException: Could not create connection; - nested throwable: (java.sql.SQLException: Access denied for user ''@'ABC' (using password: NO))
    at org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.getLocalManagedConnection(LocalManagedConnectionFactory.java:225)
    at org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.createManagedConnection(LocalManagedConnectionFactory.java:195)
    at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.createConnectionEventListener(InternalManagedConnectionPool.java:633)
    at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.getConnection(InternalManagedConnectionPool.java:267)
    at org.jboss.resource.connectionmanager.JBossManagedConnectionPool$BasePool.getConnection(JBossManagedConnectionPool.java:659)
    at org.jboss.resource.connectionmanager.JBossManagedConnectionPool.testConnection(JBossManagedConnectionPool.java:354)

Oracle

org.jboss.resource.JBossResourceException: Could not create connection; - nested throwable: (java.sql.SQLException: invalid arguments in call)
at org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.getLocalManagedConnection(LocalManagedConnectionFactory.java:225)
at org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.createManagedConnection(LocalManagedConnectionFactory.java:195)
at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.createConnectionEventListener(InternalManagedConnectionPool.java:633)
at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.getConnection(InternalManagedConnectionPool.java:267)
at org.jboss.resource.connectionmanager.JBossManagedConnectionPool$BasePool.getConnection(JBossManagedConnectionPool.java:659)
at org.jboss.resource.connectionmanager.JBossManagedConnectionPool.testConnection(JBossManagedConnectionPool.java:354)

DB2

WARN  [org.jboss.resource.connectionmanager.JBossManagedConnectionPool] (ResourceContainer.invoker.nonDaemon-1) Throwable while attempting to get a new connection: null
org.jboss.resource.JBossResourceException: No matching credentials in Subject!

(The exact error message will vary as it is generated either by the JDBC driver or the RDBMS itself.)