Yesterday night when I went to sleep, I had Windows Vista running in the parallels 3188 on Mac in full-screen mode. I was editing some documents, and left the OS running in full-screen mode as is…but when I woke up in the morning after 6-8 hours… I could not able to get the control to OS back. Parallels grayed the OS, and nothing is working. I tried to change it to window mode, coherence mode and to full-screen mode no use.
Looks like there is a bug in Parallels where in if the guest OS goes to sleep (I had windows to goto sleep in 1 hour) and Parallels does not have any control over the OS. Anyway, upon clicking stop and rebooting back..everything started working. I noticed that stop and start back resulted a reboot.