I have more or less the same problem.
It works perfectly fine in Cubase 8.30 Win7/64 in a fresh project... right until you make some progress in the track, then the project starts to get really unstable. Also trying to add the virus to a mature project in the VST Rack causes instant crashes most of the time. Sometimes the project won't even open until you shut off the virus. ASIO Guard is off so that's not the problem.
It helped somewhat for me to get a powered USB 2.0 Hub and connect it to a USB 2.0 port. Only the virus goes to the hub, and the hub is the sole connection on a USB 2.0 PCI card. At least it's usable now.
This system is a bit unstable in the USB department, not sure if Windows or Mobo setting, or whatever but regardless the Virus worked flawlessly with Cubase 5 even without a hub.