Problems specifying SFTP cipher aes256-ctr

Symptom

Using Gentran Integration Suite 4.3 build 4323.   Gentran Integration Suite is the the SFTP server.   The SFTP Client is also Gentran Integration Suite build 4323.   The auditor requires xxxnnn-ctr ciphers to be used.  For example aes256-ctr.   

The SFTP client receives a message about invalid message length.   The SFTP server generates an error that the SFTP Client sent a message with invalid length and a DoS attack is being attempted.  

The connection works successfully when the SFTP Client specifies cipher aes256-cbc.   The problem appears to be with ctr ciphers.  

The error below is from the SFTP Common Log in verbose mode.

[2011-01-07 12:33:50.041] ERROR 000000000000 GLOBAL_SCOPE ** MAVERICK SSHD ** Connection Error
java.io.IOException: Client sent invalid message length of -840192746! Possible DoS attack
    at com.maverick.sshd.TransportProtocol.B(Unknown Source)
    at com.maverick.sshd.TransportProtocol.onSocketRead(Unknown Source)
    at com.maverick.nio.SocketConnection.processReadEvent(Unknown Source)
    at com.maverick.nio.Daemon$_C.processSelectionKey(Unknown Source)
    at com.maverick.nio.SelectorThread.run(Unknown Source)
[2011-01-07 12:33:50.041] INFO 000000000000 GLOBAL_SCOPE ** MAVERICK SSHD ** Disconnecting: Failed to read binary packet data!
[2011-01-07 12:33:50.041] INFO 000000000000 GLOBAL_SCOPE ** MAVERICK SSHD ** Posting message com.maverick.sshd.TransportProtocol$_A to queue