If I hit forward and back in Chrome, my text doesn't disappear and I don't have any addons. I just tested it with this post. What browser are you using?
Firefox, i believe because I have scripts blocked, just came to mind, beat tired.
*shrug* I use 11.12 and 12.1 for all my miners and none of them need dummy plugs.
I wonder if because I have in bios, graphics set to onboard "intel's graphics". But I have it set at this, as explained in op.
But other than that, I've got two cards mining away nicely.