Seam in tileSprite

[blameMike]

I have two backgrounds that are tiled (this.game.add.tileSprite) and moved in the update function to simulate movement of the player. In Chrome (doesn't happen in Safari) I get a weird seam http://cl.ly/image/3E3V0G0t2X1E where the images meet up upon scrolling. I'm using texture packer for my backgrounds. 

 

My update code is like:

    this.background.tilePosition.x -= 1;

Any insight would be lovely. Thanks.