PLP1000 with Virgin Media, constantly disconnecting ethernet connection

michaelkenward knows what they're doing with powerline. 

And more than likely right. Its doubtful that the hub is causing the issue. 

Its more likely related to something in your powerline system thats injecting interference. 

things that can cause issues:

surge protectors

gfci outlets

arc fault outlets

electronics going bad

cheap cell phone chargers

old/bad wiring

high draw appliances

Basically if it was working fine before and it works fine at other people places, I'd be looking at what devices you have plugged into your network.