On firefox the screen is split in half

Unity Engine
1

Hey guys, good morning!
I´m new here. I´m a long time user but it´s mine first time posting.
We finished this game.
But for some reason on the firefox of our cliente the game screen is split on 2, like this image below.
HE is using a mac with os x 10.9.3

PLease Someone have any idea, of what is happening?

Thanks very much

1655245--103355--firefox.png
1655245--103355--firefox.png970×649 392 KB

2

We discovery that it´s just happening with mac.
IT’s a facebook game.
Would be awesome if someone could give us a light.

3

So, since no one knows I`m assuming that it´s something related with our game and not unity,