Noticed the same, a sudden go slow, (not a complaint or anything!! cuzit's awsome). I've noticed the same thing happening with any sites that use adservers, bbc ok, sky pants, etc. Got concerned, like to keep me machine clean, cleaned really well. Another common factor maybe AVG free? When it updates it resets your settings, I always have the identity protection disabled, slows firefox terribly and makes it all seem sticky. Turn it off and things improve a lot. It's not a fast machine but 20Mb internet wired. Even when very slow, still getting 19.7. So my moneys on AVG.