OK, just told OH about this thread, he's the one in the know!
Apparently there is a bug, I am now going to type what he says to give you the info
'If you go to your router (address 192.168.0.1) in IE (Internet Explorer), on the left hand menu there is an option called UPnP, this will bring up an additional menu in the centre of the screen which will have an option "turn UPnP on". The box next to it will be ticked, untick it, click apply and your router will be a lot more stable.'
OH reads a lot of techy forums etc and he found this out on one of them, apparently sky don't know about it.... why hasn't somebody told them? LOL!