Hi, while running our application we found that Queue message to MDB is delivered , the same message is again being delivered after delay of some time. Even though there is no exception...the first message is still under process. Do we need to do something to change the behaviour ? We are using JBM1.4.0SP3 n JBoss AS 4.2.3 , Client is sending message with AUTO_ACKNWLEDGMENT n Transaction is set to false. DB persistence is configured to MySQL Can Msg.acknowledge(); help in this case ?