(Note: I have solved this problem, but it took long enough that I\'m posting question/answer here.)
The Xcode build process \"optimizes\" my PNGs when build
For all you guys using Xcode 6.4 and above:
Go to: "Targets" - "YourProject Name".
Next go to the "Build Settings" tab. Just below the Tab name click the "Basic" and "Combined" Button.
Next scroll down to the "Packaging" seperator and you will find "Compress PNG Files" set to "Yes" by default.