Hello I'm experiencing the same problem.  I'm trying to get the embedded-jboss-beta3.SP10 server up and running after replacing the hqldb-ds.xml and hqldb-persistence-service.xml I run into the same problem.

[java] org.jboss.deployment.DeploymentException: No Attribute found with name: DetectDuplicates for jboss.messaging:service=PersistenceManager, attributes: [DataSource, Instance, SqlProperties, UsingBatchUpdates, TransactionManager, CreateTablesOnStartup, SupportsBlobOnSelect, UsingBinaryStream, UsingTrailingByte, MaxParams]

However the DetectDuplicates attribute is present the states it isn't for the service jboss.messaging:service=PersistenceManager.  I'm sure about looking in the correct file if the program displays it correctly of course.

[java] vfsfile:/D:/dev/workspace/embedded-AS-plain-java/bootstrap/deploy/messaging/postgresql-persistence-service.xml ->

postgresql-persistence-service.xml looks as follows

<mbean code="org.jboss.messaging.core.jmx.JDBCPersistenceManagerService"
      name="jboss.messaging:service=PersistenceManager"
      xmbean-dd="xmdesc/JDBCPersistenceManager-xmbean.xml">

      <depends>jboss.jca:service=DataSourceBinding,name=DefaultDS</depends>
      <depends optional-attribute-name="TransactionManager">jboss:service=TransactionManager</depends>
      <attribute name="DataSource">java:/DefaultDS</attribute>
      <attribute name="CreateTablesOnStartup">true</attribute>
      <attribute name="DetectDuplicates">true</attribute>
      <attribute name="IDCacheSize">500</attribute>
      <attribute name="SqlProperties"><![CDATA[
       CREATE_DUAL=CREATE TABLE JBM_DUAL (DUMMY INTEGER, PRIMARY KEY (DUMMY))
       CREATE_MESSAGE_REFERENCE=CREATE TABLE JBM_MSG_REF (MESSAGE_ID BIGINT, CHANNEL_ID BIGINT, TRANSACTION_ID BIGINT, STATE CHAR(1), ORD BIGINT, PAGE_ORD BIGINT, DELIVERY_COUNT INTEGER, SCHED_DELIVERY BIGINT, PRIMARY KEY(MESSAGE_ID, CHANNEL_ID))
       ..................................
      ]]>
      </attribute>

      <attribute name="MaxParams">500</attribute>
      <attribute name="Clustered">false</attribute>
   </mbean>

I tried to fiddle a bit with removing attributes.  I removed the DetectDuplicates attribute and guess what?  The program said it was missing the IDCacheSize attribute - the next one in line.  When I removed the IDCacheSize, the startup procedure stated it was missing the SqlProperties.  It's like what is on that location he can not find for one reason or another.  I also tried to duplicate the DetectDuplicates on different locations but it didn't help either.  Anybody, any ideas?

Thanks in advance for your time and support.

Marc.