first hints: you shouldn´t expose usernames, dns-names and ip-addresses of your internal network.
Now to your problem:
Which agent version are you using? In case of 5.0.6, the most current one, I think they just released a fix and if I remember right there was something about fixing the timeouts.
Maybe you have a look at the newest fixes and releasenotes.
This is the 506.220. I see there is a later version of the agent for the Mac, 506.347, and we do have some installed so, I will try those and see if there is a difference.
Still a problem, even with the most recent agent. I can sometimes get a quick response when only wakeing up a single system, that I know is on-line, anymore than that, the process will stall at 50 to 80%, and just sit there forever, till I end it.
Okay that´s strange then.
Maybe you want to call McAfee directly about this?