Stephen,
What's your recommendation as far as restarting services are concerned: is it best done via virtuozzo, via plesk, or via the msc interface?
Since our enfant terrible plesk likes to control everything and do things in its own special way i'd be tempted to say via plesk, but if the service in question (e.g. IIS) is hanging precisely because plesk has somehow choked on a byte or two, it often doesn't seem to do the trick.