Its got to be connected if they both have the same thing and came from the same place. Have you tried a natural germ and bacteria killer like garlic? Maybe feeding them a clove or two might help them fight off what ever it is. I might even go as far as crushing some up and washing their head with it.
Just don't eat any eggs for a while after. I hear the garlic makes them taste funny.
You may also want to call the place you got them. They may know what it is and how to treat it since it sounds like they have an infected stock.
Wish I could tell you I knew what is was. Good luck.