"Forefront TMG management cannot establish a connection with the Forefront TMG computer" error on Standalone Array Manager

I have 2 TMG servers with 2 network adapters. I followed next article to deploy Standalone array:

http://technet.microsoft.com/en-us/library/dd440981.aspx

After these task I have this error in Monitoring -> Configuration (Array Manager console) on the Array Managed server:

"Forefront TMG management cannot establish a connection with the Forefront TMG computer"

If I go to the Array Managed server console it is ok.

I have both servers added to "Managed Server Computers" and "Enterprise Remote Management Computers".

I need help to fix this issue.

I see this post:

http://social.technet.microsoft.com/Forums/en-US/Forefrontedgegeneral/thread/80f2a2f5-0b7e-4fc0-833f-a2e0e6651da5

But Do I need the cert if the server are domain members?

Also intra-array network adapter are required or recommended?

Thanks,

Dario Woitasen | MCSE Lync Server 2013 | MCITP: Enterprise Messaging Administrator 2007/2010, Lync Server 2010 Administrator