Download Insight Not always checking...

TinFoil hat time, I noticed if I download Firefox from firefox's main site. http://www.mozilla.com/  NIS 2010 isn't poping up with a Green firechecked by norton download insight. are some domains not check? or if I've already downloaded a file does it just assume that it's safe and not alert me? I tried this with ie8 and it did the same thing. but if I download a file from another site not the same file it works, strange,

 

 

tested on three computers all running NIS 2010, 177012, window xp, windows 7