Pixel perfect render texture sprites moving irreguarly

I'm creating a pixel-art game in unity, I've been using a render texture to have the graphics pixel perfect. At the moment I'm using this guy's scripts, they're pretty neat; https://github.com/prime31/PixelPerfectCameraKit

http://i.imgur.com/k9Arv65.gif

Whilst the graphics do appear perfect in their appearance, the positions of individual sprites seem to jump irregularly. I understand that the sprites need to jump from pixel to pixel, but they all jump at different thresholds, with just looks very ugly.

I've tried enabling/disabling pixel-snap in the shader, but it doesn't seem to do much. Here are the settings I'm using;

http://i.imgur.com/rMqTwi4.png

(for some reason I cannot embed the images, sorry) any ideas?