Can anyone help me resolve a *maddening* (recent) issue: BACKGROUND Currently using Firefox (v. 43.0.2 ) on a MacBook Pro (v.10.11.1) The issue (described below) only, but *always*, occurs at this web site, to which I go daily: http://internacional.elpais.com/ It never occurs elsewhere. NOTE: 1. The above URL is the web site for one of Spain's main, national newspapers. It's equivalent to NY Times in US, The Guardian in UK etc. 2. The problem has developed recently, and, as stated before - never occurs on any other web sites. Nor does it occur if I use Safari at this site (which I don't wish to do) ! PROBLEM DESCRIPTION: The above URL opens the following: (see screen shot attachment #1). Obviously, as it's a newspaper, the page content will change daily, but its format remains the same. And....that opening page is always fine (no issue there). However, any and all links on that page will, in turn, open pages which are always divided into 2 vertical columns or panes. (See screen shot attachment #2). And the link (just clicked on) always opens in the left hand column . The right hand pane always contains links to "Latest News", "Latest Videos", "Recommended Articles". etc. etc. etc. going down the length of the page. It takes up almost 1/2 the width of the screen. And ......***that entire right hand pane flashes on and off, like clockwork, every 6 seconds - or more precisely - it's ON for 6 seconds, OFF for 1 second, ON for 6 seconds, OFF for 1 second, ON..........ad nauseum....making it almost impossible to concentrate on what one is attempting to read (in Spanish!) in the left hand pane!!!*** It's totally distracting and finally untenable. (See screen shot attachment #3 - taken 1 second after attachment #2 - and you'll see the right hand pane has momentarily disappeared, leaving empty space). I'd be grateful for any insight into what might be causing this one web site to behave so annoyingly. Since I'm not experiencing this issue (or any issue, for that matter) elsewhere and since this does not occur if I use Safari - I have to surmise there is a weird interaction between Firefox and that specific web site. But what might it be?