Weird issue with two cameras and effects

I have two cameras in my project. Everything works fine on Windows, but on OS X something strange happens when both cameras have a post processing effect enabled.

See here: http://i.imgur.com/rKSJkJA.png , on the left is when only one of the cameras has an effect applied, the right image is when I apply a vignette to the second camera.

Any ideas what may be causing this?

It seems this is a bug in 5.3.3, upgrading to 5.3.4 makes this work properly.