Not only is the problem with apple if you also with windows with the new Core i5/i7 haswell, and you should also be aware of the changes, I find it takes too long to develop drivers, even pace with Mountain Lion, you remember?, and the beta driver was months without change, I think is a serious mistake to you, not to investigate and anticipate problems that may arise with new technologies, it is so serious that leave thousands of users with their jobs half way ....
purchase a mac mini with Haswell I5, and my 1818VSL does not work anymore, it's amazing that they have not yet developed a driver support, I am very disappointed with the support presonus gives its users, I stopped all my projects, waiting for some solution.