I get this, too, although perhaps not as frequently. For my part I believe it occurs mostly with UK online newspapers and is perhaps caused by the adverts.
Annoying, but I just let it reload.
I wonder whether trying another browser might help. I have been experimenting with the browser Mercury, as it can load pages without displaying images. I cannot comment at present as to your problem but will try and see if it is any different. (Using another browser does introduce another pain- exporting bookmarks from Safari...)