when you do a collect and recieve properties do you get and error " agent faield to communicate to epo server ?"
If this is the case then do frminst.exe /install=agent /forceinstall
this is to be done in command prompt in the common framework directory.
You can install the Mcafee antivirus on the server manually , then do the agent install after that . (if it is a 64 bit node , please remember to right click ---->run as administrator)
We had the same issue where some of my workstations did not come up as managed on the ePO, I re-installed everything, but still to no avail, but after a re-install of the framepkg.exe and a reboot of the workstation afterwards the workstation came up as managed on my ePO.
I hope this helps.
just a thought... did you try turning any software firewalls of on the machine in question?