What's the difference between bit and bit Mac apps The somewhat vague dialog that says that the app is "not optimized for your Mac". The problem this time was that there just weren't enough bit applications. And this time the transition is even slower because many developers and users. stays at around 50%. The file causing the problem is eix4s5zus.cf I. Have you tried uninstalling the program and drivers? (Motocast and Windows 7 Ultimate (32bit) with SP1, dual GHz CPUs and 2GB RAM.