This issue has been annoying me for some time but since the upgrade to Snow Leopard it now seems to be happening every time. When invoking the OS X Application Switcher via Cmd+Tab while Parallels Desktop is the front window and a Windows VM is running the Cmd keystroke is always received by the VM and results in opening the Start Menu. This means that whenever I return back to Parallels it is necessary to close the Start Menu before I can interact with the application that I had open in the VM.
Parallels Desktop (4.0.3846.436204) is currently configured via the Keyboard Preferences to "Enable Mac OS X system shortcuts" yet this shortcut, or at least the Cmd aspect of it, is still being received by the VM. This should not happen.
Parallels Desktop (4.0.3846.436204) is currently configured via the Keyboard Preferences to "Enable Mac OS X system shortcuts" yet this shortcut, or at least the Cmd aspect of it, is still being received by the VM. This should not happen.