I just upgraded to Parallels Desktop 1.6. It will not boot my Mavericks VM. Everything else works. I can even boot into 10.8 and upgrade that. After the upgrade, Mavericks works, but only once. If I shutdown, it will never boot again. It just sits on a grey screen with a grey Apple logo burning the CPU at 104%. I did create a snapshot during that first boot. I can restore that snapshot and run Mavericks. But surely there is a way to fix this?