I had exactly the same issue with real-time scanning. Run MVT which didn't help at all. Then i updated Adobe Flash and McAfee was back to normal.
That's odd to say the least but yes, keep all add-ons up to date. Flash in particular has auto-update turned on by default, I don't recommend turning that off, if that's the case here.
It's logical to me as we've been told that the operation of the interface depends on an up-to-date Internet Explorer at default settings and any add-ons also up-to-date, regardless of whether or not you ever use the browser.
Thanks ellerhur for that observation.
Go to your 'run' (windows+r), type in 'NETSH FIREWALL RESET' and press enter. This will keep your Mcaffee real time protection from turning off.
That resets Windows Firewall to its default settings, however with McAfee/Intel consumer suites Windows Firewall is turned off and should remain off, unless in the very rare case where the consumer has refused installation of the software suite's own firewall, which hardly ever happens and is not advisable.
Am locking this thread as I assume it was solved.