Sandbox storage location is now divided per-volume, i.e. if a virtualized application creates a file on you D: volume, it'll be sandboxed on this volume. This is quite practical - we don't create avast sandbox on the fixed volume (C,D), because "C" volume can be small and virtualized files from D volume may not fit there, etc. However, this behavior will be improved in avast7 so you can manage it easily.
As for virtualized web browsers, all virtualized files from well-known webbrowsers are not deleted when you exit the webbrowser (sandbox contents is permanent unless you delete it manually in GUI).
