Wheway - You turn your router off at night but leave the HDR-1000S on?
I think the HDR-1000S may well currently only request a IP address on powerup - will play later and find out.
Assuming you are set to accurate record (Padding=Auto) then the unit will wait for a change in running status to be received for the current programme. Rarely the broadcaster forgets to send it, the unit will then think the programme has overrun and sticks with it.
With a single cable connection you have two tuner operation but the two tuners are limited in function as they can only be switched to the same polarisation (V/H) and band (Low/High) as the first. The programme must not have met this criteria or it would have switched to it.