It's a fixed version that will work everywhere. The problem was, that i allocated a ByteBuffer in native order, where i should have one allocated in LITTLE_ENDIAN. This works for Intel, because native order is LITTLE_ENDIAN there...but on Mac, native order is BIG_ENDIAN. The ByteBuffer is now always LITTLE_ENDIAN regardless of the system.
About your input problems: This is most likely a LWJGL problem. The fps-example uses two different approaches to query the keyboard. The SUN-like approach is used when using software rendering and the LWJGL-approach when using LWJGL. If this doesn't work, it's either a problem of LWJGL for Mac or i'm doing something not 100% right to query the keyboard. Then again, there's not much room to do things wrong...
Have you tried fullscreen mode on Mac? Maybe the keyboard will work there!?