I have recently developed the following problem. I can launch Parallels v3.x without a problem. Whenever I try to start a VM, either XP or Vista, it starts to launch and then my whole Mac locks up. No mouse, video, etc....... The only way to escape is to hold down my Mac power button to force a shutdown. This was true of v3.x build 4128. I just downloaded the new build. Same problem. Any thoughts? Up untill a week ago, it all was working with a problem.