Hi, I've been running Windows 7 in Parallels Desktop on my MacBook Pro, which itself is running OS X 10.8.3. Until last week, when I had Parallels 7, everything was pretty well fine. But since I upgraded to Parallels 8, each time I click on a Windows app in my Dock to launch it I hear a very brief, very unpleasant noise. It's like a short burst of static or radio interference. I haven't a clue where to start looking for a rectification for this. Can anyone help please?