This subject is a regular on this website, and it would seem to be the views of a number of forum members that it might be down to java script.
I tend to find that Google Chrome works the best, with Mozilla Firefox second, and Internet Explorer a poor third. So I would perhaps suggest that you might give Google Chrome a try, and see if the problems remains.
I do not believe that Java Script is the main problem.
It may be problematic but in my opinion the Main Problem is causes by the number of 'bytes' required to be downloaded every time you change a page on the site.
My experience is that the initial page loads but that one cannot access it, for a considerable period, until all the Adverts have loaded, particularly the 'surrounding' Advert.
The Surround Advert causes another problem as, if you 'click' on a link before it has fully loaded, the page moves down an inch or so and one finds that one has clicked on a different link, so one has to wait even longer while the original page re-loads.