Hi,
I'm confused as what you classify as VPN traffic. In looking at my own reports as well as the reports on your demo server, there is little difference between VPN reports and conversation reports. In fact, most of the items on the VPN report would just be normal unsecured traffic. Why are the VPN reports including web and mail traffic? This problem appears across all brands of devices it seems. I would assume that only IKE/ESP/PPTP or maybe even SSL would appear in this report but not traffic that is not tunneled.