I eagerly awaited the release of P4, because I had problems with P3 -- mostly cured by turning off the sound. The sound on in P3 caused regular crashes. P4 crashed twice during the install, and finally I had XP launched and parallels tools installed. Of course, it crashed a few minutes later and then would not let windows get past the login screen where it crashed, even in safe mode. After a few of those, it could no longer find the hard drive. So I tried reverting to an older snapshot, which crashed immediately. Now I'm reverting back to P3. Wasted a day on this one... upgrading (into uselessness?) the P3 virtual machines takes several hours. Enjoy. This one gets an "F"