you don't need to clone the mac address-
when you provisioned the router, this registeredd it's mac address to the ntl network, hence no need to clone the pc's mac, as this would also require provisioning.
If i were you do the following:
- Disconnect and power down STB
- reset router to factory settings
- power up stb
- connect router to stb
- provision router
- reboot stb and router
- Try the wired connection if AOK try the wireless connection.
Sorted