Java EE (Java Enterprise Edition) General Discussion

Hi,
we are getting the following kind of errors in the Sun JES Message Queue:

[19/Apr/2007:09:29:02 CEST] ERROR [B3100]: Unexpected Broker Internal Error : [Unknown transaction: 4496019631547352064(4496019631547352064
) broker will  not notify the client Ignoring ROLLBACK_TRANSACTION(48)
         Packet: ROLLBACK_TRANSACTION(48):51129576-5.64.18.250(cd:d5:e6:4d:82:dd)-53817-1176967742143
  Magic/Version: 469754818/301  Size: 112        Type: ROLLBACK_TRANSACTION(48)
     Expiration: 0                     Timestamp: 1176967742143
      Source IP: 5.64.18.250(cd:d5:e6:4d:82:dd)  Port: 53817    Sequence: 51129576
Property Offset: 76                     Property Size: 36
     Encryption: 0      Priority: 5
          Flags:                           consumerID: 0
     TransactionID: 0
       MessageID: 51129576-5.64.18.250(cd:d5:e6:4d:82:dd)-53817-1176967742143
     Properties: {JMQTransactionID=4496019631547352064}
   Message Body: 0 bytes
Internal Buffers (useDirect=false):
    Fixed Header Buffer:java.nio.HeapByteBuffer[pos=0 lim=72 cap=72]
]

and also

[19/Apr/2007:09:29:02 CEST] ERROR Transaction ID 4496019631547385344 has already been resolved. Ignoring request: ROLLBACK_TRANSACTION(48).
 Last state of this transaction: guest@replicationmanager:COMMITED(6) broker will  not notify the client

Do you know why it appears? Do you know what is the reason behind it?
We suspect that these errors are symptoms which manifest after several hours in the following:

[19/Apr/2007:23:38:07 CEST] [B1089]: In low memory condition, Broker is attempting to free up resources
[19/Apr/2007:23:38:07 CEST] [B1088]: Entering Memory State [B0022]: YELLOW from previous state [B0021]: GREEN  - allocated memory is 155588
K, 80% of total memory used

Here is version information from "/opt/sun/mq/bin/imqcmd -v":

Sun Java(tm) System Message Queue 3 2005Q1
Sun Microsystems, Inc.
Version:  3.6  (Build 146-W)
Compile:  Tue Oct 19 14:56:24 PDT 2004

Our application consists of two processes:
1 process with 1 producer, which creates a durable topic and publishes to it
1 process with several consumers, which consume messages from the topic

If more information is required, we can provide them on request.

Thanks a lot for answers.
Ivo Raisr