Thank you very much for that link, BTNH108464.
The article does not seem to address FF 4, which I am using, so I decided to try setting the values to false and seeing what happens. Pleasee see attached image for the exact changes I made.
After setting both values to false restarted FF and went to: eicar | THE ANTI-VIRUS OR ANTI-MALWARE TEST FILE
I downloaded some normal safe files and then downloaded some virus test files from EICAR. FF 4 did not scan files but MSE did catch the eicar files. I assume this means that the FF values are not overriding Window's security policy checks.
is this a safe assumption?