12 JCK tests fail on Mac OS X with b227. Most of the failures are due to incorrect positioning of the splash screen: it is shifted 24 pixels lowere than expected by the JCK test. This is because OS accounts for the main menu bar and relocates the window automatically.

Note that there's a number of other failures related to wrong colors when checking the image of the splash screen, but those will need to be fixed separately after fixing the positioning issue.