Thanks for the reply. It stopped happing once I updated the MapMagic asset. I was on version 1.7 but the asset store said there was an update (still v1.7???). It might have been a problem with the retina screen since I was on my laptop where it was happening (but it wasn't a problem on my desktop). Since the 1.7 release notes mentioned a retina display fix I am guessing that was the problem. cheers, Richard.