I use Parallels Desktop daily to virtualize Window 7. I am running a MacBook Pro(3,1), Core 2 Duo 2.4GHz, 4GB RAM, 500GB 7.2K HD, Mac OS X 10.7. After 3-4 hours Parallels become sluggish and nearly unusable. Dragging a window can take 3 minutes before it moves. I decided to run Activity Monitor to see if I was using too many resources. RAM usage looked okay, but the CPU utilization is maxed out. Even after I quit Parallels I have two prl_vm_app processes running and both are consuming nearly 100% of each core. I think this is a bug. I've reinstalled Parallels and the problem persists. I have Mac Pro that I use and am not sure if the problem can be recreated there, but I'll check later. Any thoughts?