Data Domain ifgroup part III

We try to config ifgroup with NetWorker 7.6.1, and it fails to work as expected.  For ex, if I setup ifgroup with 2 dual 10GbE NICs, and unplug a cable.  Sometimes, I don't see the backup session failovers to the other 3 working NIC.    If I set up failover on the NICs of DataDomain, I don't have any issue as mentioned in my earlier post.  Contact support and the suggestion is to upgrade to NetWorker to 7.6.2 and the DDOS to 5.0.  I am happy with NetWorker 7.6.1 and DDOS 4.9.x for now.  Will decide when to upgrade in the future.  Currently NIC failover on DataDomain is good enough!