I've narrowed this down. All of the times that this happens for me is when I have Chrome open, and I receive an incoming "+1" in Google Plus. Not every "+1" triggers this, so I suspect that there is a secondary part to the trigger; possibly switching tabs.
I've narrowed this down. All of the times that this happens for me is when I have Chrome open, and I receive an incoming "+1" in Google Plus. Not every "+1" triggers this, so I suspect that there is a secondary part to the trigger; possibly switching tabs.