I've had the same subperhub for a years now, and no real problems so far, then without any obvious change or cause, there's an issue with it.
Wired devices seem to cycle between "disconnected", "obtaining ip address", "connected with no internet" and "connected with internet"... only having the internet for five or ten minutes at a time. Wireless devices just don't seem to even attempt connecting via wireless, and the SSID is sometimes available, sometimes not. I can no longer reliably access my network storage, log into the superhub or ping any LAN devices.
I've tried a hard reset with the recessed switch, a soft reset using the routers "reset superhub to default" option, power cycles, connecting single devices at a time to see if there was a device causing an issue, checking the coax cable to the router is secure, Checking Ethernet is securely attatched, ringing Virgin up and explaining the problem... and none of these things seem to remedy the situation... not even temporarily.
I use the router a lot as a local network, so it seems to me that there is an issue with the router itself considering that if there's been a local internet blackout in the past I can still use my NAS and other computers... and considering a factory reset hasn't seemed to fix anything.
With no SSID and that the router has been doing this for almost a solid day (and it's had a while being left turned off)... I'm worried that the superhub is starting to fail.