Separate names with a comma.
I had this problem also.
Solution Just uninstalled and re-installed Parallels 7.0.15106.786747. Seemed like a longshot, but it worked. No delay in shutdown now, after...
Addition This is Parallels v. 7.0.15106.786747 with Mountain Lion. In the first sentence above, i meant "thread" not threat. Parallels Win7...