Backups Fail if iscsi is running on ABR 11

Version:
11.017318

OS: RHEL6.2 (using Centos 6.2)
Hardware: Dell 715 server with 10 network ports
SAN: Dell MD 3200i with dual controllers, 4 ports each

Server is connected to SAN using 4 network ports using iscsi and multipath. The rest of the network ports are for connected to two separate VLANs.

I install ABR11 Virtual Edition on server. I can browse all filesystems of the server including iscsi drives from the management server. However, attempting to backup files to a central vault results in the following error. This includes files on the local drive on the server.

Failed to connect to the process.
Additional info:
--------------------
Error code: 11
Module: 300
LineInfo: 2a463402369021a2
Fields: $module : /usr/lib/Acronis/BackupAndRecovery/mms
Message: Failed to connect to the process.
--------------------
Error code: 12
Module: 300
LineInfo: 2a463402369021a3
Fields:
Message: The operation has timed out.
--------------------

If I turn of iscsi service, then the backup succeeds of files in the local drive. However, if I turn the iscsi service on, then I get the above errors. Looking into the logs on the server I see that the iscsi drives are being disconnnected and reconnected. The SAN (MD 3200i) has logs showing that the iscsi connections are lost. I am concluding the acronis service is attempting to initiate connections on the network port dedicated to the iscsi. There is no reason to use this port as the management server and vault are not reachable through this interface. I have tried with firewalls on and off, exceptions for port 9876.

In debugging this issues, I reduced the configuration to stop using multipathing and use only one network port for iscsi. I was then able to by adding iptable rules make a backup with iscsi running. But I don't understand what is going on and I didn't document my experiments. I will try getting it to work by modifying iptables, but I need to know the root cause.