I had issues with my Fritz 4040 Router when running a BQM due to it couldn't handle all the pings and after a while it started to drop ping packets.
As for if its VM Equipment causing the issues I wouldn't know due to I will never be able to get VM here due to being a conservation area so no VM Cabinets down my road, not that I would go with them.
The reason I ask is that the PSU in the Superhub might be bad, or the Superhub might not be shielded good and RF might be leaking which is interfering on your Zen Connection.
Also how close are they together?
As for your IP changing all the time, ISP can change them without the need to reboot the hub.
BT do this a lot, some times my IP will stay the same for a month or two and another time it might just last a couple of weeks.
Paul