The Auto Failover is on the DSS V6 side and I was thinking that maybe it was incorrectly setup for the SCSI ID's or Target Name and LUN# that has to match. If your not using this feature then we can then look at the logs to see if two initiators are accessing the LUN but logs would be needed to see or you can look into the test.log file and search for the session heading to see what it connected.