Hello Paralells 7 has some great new features, still feels a little buggie, but a step insight direction, there are a couple of suggestions I have related to full screen mode. When you create aGuest VM and open it up, I find that it remains open up on the original desktop it it was last present regardless of which desktop the Virtual Machine List windows is set to open on. So I open Parallels on DEsktop 3, and open a VM ion Desktop 3 as that is what I want, during the cause I move the VM to say desktop 2, then close, when I next start parallels the Virtual machine list open on desktop 3, but the VM opens in the Desktop 2 which is were it last was open, this might be correct functionality as expected. I would be nice if there was configuration option to select which Desktop you'd like to open your VM machines? maybe an option when it open to assign it a desktop, that way you have you VM's open in windowed environments on different desktops if you wish.
I think this may be a feature of Lion that is enabled by default. Go to System Preferences and General. You will see the following option enabled "Restore windows when quitting and re-opening apps". You can try disabling it and see if that gives you the desired results.