I installed zlib-1.2.7.1 and then built pngcrush with it and libpng-1.6.1rc01 on several platforms and found no issues. Ubuntu 12.04.2 LTS with gcc-4.6.3 SunOS 5.10 with gcc-4.7.1 SunOS 5.11 with gcc-4.8.0 FreeBSD 8.0 with gcc 4.2.1 Glenn ----- Mark Adler <madler at madler.net> wrote: > zlibbers, > > Please take a look at zlib 1.2.7.1