I'm running / coding a Qt app which uses QImage to load PNG files. On Windows it works fine, but on Linux I get:

Qt Code: 
  1. libpng warning: zlib version error
To copy to clipboard, switch view to plain text mode 

and then it won't load the PNG. this is with Qt 5.2.1 as downloaded from the Qt server, on Ubuntu 14.04 64 bit. I wonder what is wrong / how this can be fixed?