Some pages are constantly loading

Sometimes in Firefox form pages load fully, but then sit there constantly loading afterwards, only stops if I close that window.
Completely random, pressing the stop button in my browser doesn't prevent it happening either.

Obviously connected to the advertising, and whatever shoddy code they are inserting into the page.

I haven't noticed any issues today, but have seen what you're talking about before. In Firefox, if you right click on the page and go to "Inspect Element" there is a "Network" tab there where you can see what file specifically is consuming time. If you could check and let me know so I can figure out where it might be coming from, that would be very helpful I know we had problems with eBay ads before slowing the page down quite a bit.