JBoss AS start fails if used configuration is not default one

When starting the 'default' configuration everything is fine, but any other config fails. I've got the following error:
"Server JBoss 3.2 Runtime Server failed to start.
An exception stack trace is not available."

After searching the filesystem for any clues or hints what's going wrong, I found a logfile in the metadir of my workspace @
".metadata\.plugins\org.jboss.ide.eclipse.as.core\JBoss_3.2_Runtime_Server\log" with the following content:

!ENTRY org.jboss.ide.eclipse.as.core 4 16842752 2009-10-14 10:19:48.580
!MESSAGE Failure in Poll Thread
!STACK 0
org.jboss.ide.eclipse.as.core.server.IServerStatePoller$PollingException: java.lang.Boolean cannot be cast to java.lang.String
at org.jboss.ide.eclipse.as.core.extensions.polling.JMXPoller$PollerRunnable.handleException(JMXPoller.java:166)
at org.jboss.ide.eclipse.as.core.extensions.polling.JMXPoller$PollerRunnable.run(JMXPoller.java:106)
at java.lang.Thread.run(Thread.java:619)

After that I switch the Server Polling method from "JMX Poller" to "Timeout Poller" and the server starts, but the plugin never reached the state "Started" - it remains in the the state "Starting".

In the default config the JMX Poller works as expected.