Do you still have the Thomson modem in place? If so, do you have a 3-hole TV socket at home? If yes, then I recommend you get a so called wiclic splitter for free at the nearest upc cablecom shop or order one with our support team. Then reconnect again TV and modem and then both should be working fine.
In case you have a 2-hole TV socket, then you will need the multimedia adapter, also availabe in our shops or to be ordered.
Hope I was able to help. Should you need further support, happy to assist!