JavaEE5.9.3.1 cartridge - Data collection on JavaEE agents starts and stops on its own (4322465)

We upgraded our Java cartridge to 5.9.3.1. Since then, the older agents pre 5.9.3.1 are not reporting to nexus properly.Data collection on JavaEE agents starts and stops on its own

The error seen in the logs were:

2013-10-08 11:34:03.897 VERBOSE [Multiplexer: 1] com.quest.pas.common.comm.Multiplexer - IOException caught while reading or writing data; connection: java.nio.channels.SocketChannel[connected local=/10.xx.xx.xx:41705 remote=/10.xx.xx.xx:62485]
java.io.IOException
 at com.quest.pas.common.comm.MessageConnection.readBodyComplete(MessageConnection.java:351)
 at com.quest.pas.common.comm.MessageConnection.readComplete(MessageConnection.java:275)
 at com.quest.pas.common.comm.AbstractConnection.read(AbstractConnection.java:139)
 at com.quest.pas.common.comm.MessageConnection.read(MessageConnection.java:202)
 at com.quest.pas.common.comm.Multiplexer.read(Multiplexer.java:338)
 at com.quest.pas.common.comm.Multiplexer.run(Multiplexer.java:120)
 at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
 at com.quest.pas.common.nodekey.JdbcNodeKey.calculateHashCode(JdbcNodeKey.java:204)
 at com.quest.pas.common.nodekey.NodeKey.hashCode(NodeKey.java:141)
         at java.util.WeakHashMap.get(WeakHashMap.java:348)