LOL Info. I think your confused. First you must check off Firefox as a web browser under the HTTP tab. If its not there then add it. Then after using Firefox for 5 minutes or so close it out and now go back in to NOD32 and check off Firefox under the active mode tab. There should be no slow downs of anything. But then again I have a 6 MB DSL connection and never notice any slow downs of anything.
Ok, I guess you've never heard of the particular setting. I've been very tired lately and I got my settings confused. But there is a setting in nod 32 that puts firefox under maximum efficiency, but steals performance. When playing media, NOD 32 will download the media into nod's cache, scan it, if safe nod will then feed the downloaded media to the browser.