I've been using Parallels for months with few if any problems. I just upgraded to 3186, and the product is unusable. The installation went fine (after trying for days to download the DMG file). But, when the VM runs, the Windows desktop is completely black. I purchased a service ticket for $30, and I've been trying to get help for 3 days. Support is non-existent. Has anyone experienced the same problems with the VM or with the support crew?