Here's where I think the "bugginess" lies in this issue.
What the user would like, is to be able to disable all real-time protection
in the program and have it completely disconnected from all such
interactions. And then, of course, they'd like to be able to enable those
things again, and have it re-connect--all, preferably, without a reboot.
However, Microsoft Antispyware hooks the Shell Execute Hooks:
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Explorer: Windows Shell Execute Hooks
A shell execute hook is a program that is loaded into the Windows shell,
which is Explorer.exe. A shell execute hook program receives all execute
commands that are run on your computer. This type of integrated program can
either accept or reject a command to run a particular program.
What does this Explorer Display?
In this Explorer you can view and block any of your computer's Shell Execute
Hooks. Before blocking a Shell Execute Hook, please be aware that blocking
certain Shell Execute Hooks can cause your computer or some of your programs
to stop functioning normally.
--------------------------------------------------------------
This hook requires a reboot to change--that's the reason that the upgrade to
..509 requires a reboot, for example.
Some systems, and I think this thread may be about one of them, see a
noticeable performance issue apparently related to this hook.
This can be alleviated by either ensuring that the background process
doesn't run, or using the KB article I posted.
Unfortunately, just turning off real-time protection in the UI doesn't fix
the issue in this case.
(However, bear in mind that I'm mainly a network admin type, rather than a
programmer, so I may not have dotted all my t's and crossed my i's!)