PROBLEM WITH "LOADING " MARKETS

I have had an ongoing problem when navigating from market to market. Instead of the market loading instantly it often takes over five seconds to load which makes betting on the site ridiculously slow. The following message appears " LOADING Please wait while the market loads. "
The Betfair Helpdesk are dealing with this problem. I have sent them several screenshots of the Loading message and of my Task Manager processes.  They tell me that no-one else is experiencing the same issue. I know of three people who say they get the same problem. The issue is erratic and sometimes markets do load instantly but more often than not it is just too slow.
I have cleared cache and cookies. Problem is on Chrome Firefox and IE. I done a speedtest and got 6.60. Bought a new router. Probelm does not appear to exist when I am not logged into my account. I use a master/sub account. Windows 7. I even re-installed Chrome.
I would appreciate some advice on how to resolve this issue.