I'm having the same problems. I also have the same system. I just spent 3 hrs on line with McAfee trying to resolve the issue. Ultimately, it was not resolved and I am waiting on a supervisor to contact me. I could not get the DAT update to load. As a matter of fact no updates would load. Also, a file was missing from McAfee. I also had the on and off realtime scanning happening. I'm just about over the entire thing!
I am also in green mode and am not running any other security system.
They did try to help. It is very aggrevating!
I really don't know much about all of this other than it just seemed to happen. Computers are not my thing. But, when they work it is great...when they don't well it is not good.
I just ran a full scan, and during the scan, I got the latest DAT update, 6434 created 8/10/11.
I usually update DAT manually when I get on computer each day, as once I'm on I'm never idle, and DATS don't seem to update.
The manual DATs were failing to install and also would not install through Virtual Technician.
I'm going to keep monitoring the situation to see if I can update manually or not.
Good Luck, KR with your situation.