Sat Nav

I have a 2008 x type and i tought i would update the sat nav disc. I purchased the last disc for this model 2011- 2012. I turned the ignition on and removed the old disc and put the new one in. It came on straight away but when i select an address or post code it sends me somewhere near Barnard Castle on the Durham moors. There is also no screen on the map. I tried the old disc back in and now the same thing happens. Even when i store my home address it comes on the sceen correctly with the map and everything but when i press set as destination it takes me back to Barnard Castle with just the road with no map. Is there a reset or something?? Help please.