There was another thread about this recently. I see them like that too if I'm browsing on my iPhone or iPad for a while. (Although I haven't had it on my iPad since the latest iOS 8 update)
One of the mods posted a fix in the other thread so I'll share it here: you basically just need to do a "hard refresh" of the browser. Simply tap the refresh button on the right of the address bar twice and it should fix the problem for you!