Hi Steve,
I don’t have a solution for you but just to comment that I also have the FocusCube and connect to it via a powered USB hub. I’ve used it on about half-a-dozen imaging sessions so far and not had any problems at all. I’m also using PHD2. Nothing special about the hub, it is an old Belkin 4 port unit, but the only other device connected to it is the mount so only low bandwidth devices.
cheers
John