Sending large files cause JMSException (Connection closed)

Hello
I am using v1.1 build 31.
I am facing an issue when sending bigger files.
The test was done with ~75M file.

I reviewed all threads giving information about the issue but found no answer that can help.
I set the heap size in the LAX file to 1344M
This reduced the JMSExceptions thrown to only 1 (on mq listener 2)
Still I am unable to send the 75M file.

I redirected the LAX STDERR and STDOUT to files but did not see anything much different than the main log window.
It is listed below.

Another thing I am trying is to update the JMS Joram distribution to 5.3. Any guidelines will be appreciated.

Thank you in advance.

Milko

[2:14:52 PM] Processing the file "XYZ_SBEQ060255-49999901-99902.OUT856.OUTPUT" for the relationship "MySender/MyReceiver".

[2:14:55 PM] AS2_Server-1282241692328-0@MySenderAS2_113073472XYZ: Outgoing payload compressed.

[2:15:05 PM] AS2_Server-1282241692328-0@MySenderAS2_113073472XYZ: Outgoing message signed with the algorithm SHA-1,using keystore alias "MySenderAS2".

[2:15:34 PM] AS2_Server-1282241692328-0@MySenderAS2_113073472XYZ: Outgoing message encrypted with the algorithm 3DES, using keystore alias "MyReceiverAS2 (bizmgr)".

[2:15:34 PM] AS2_Server-1282241692328-0@MySenderAS2_113073472XYZ: Outbound AS2 message created from "XYZ_SBEQ060255-49999901-99902.OUT856.OUTPUT" for the MyReceiver "MyReceiver" in 41.86s, raw message size: 34.98 MB

[2:15:41 PM] AS2 Server mq listener 2 [javax.jms.TransactionRolledBackException]: A JMSException was thrown during the commit. [javax.jms.IllegalStateException: Connection closed]

[2:18:42 PM] AS2_Server-1282241692328-0@MySenderAS2_113073472XYZ: Transaction state written to C:\Java\AS2Server\messages\MyReceiver\sent\MySender\20100819\XYZ_SBEQ060255-49999901-99902.OUT856.OUTPUT_AS2_Server_1282241692328_0@M....