host-iMac:~ host$ idl
dyld: Symbol not found: _inflateReset2
Referenced from: /System/Library/Frameworks/ImageIO.framework/Versions/A/Resources/libPng.dylib
Expected in: /Applications/itt/idl71/bin/bin.darwin.x86_64/libz.1.dylib
in /System/Library/Frameworks/ImageIO.framework/Versions/A/Resources/libPng.dylib
remove libz.1.dylib from /Applications/itt/idl71/bin/bin.darwin.x86_64/
:)