Hi,
Sorry to hear of the problems you've been having.
As God's_Hamster says, the signal strength you see on your mobile would relate to a signal strength for calls on 2G / GPRS, rather than more advanced services such as 3G which support Mobile TV. Vodafone currently have 99.7% 2G/GPRS coverage in the UK whereas 3G (the newer service) is 73%.
It’s possible to check your signal strength by going to the below link on the
www.vodafone.co.uk website:
http://online.vodafone.co.uk/dispatc...pageID=GM_0067
Hope this helps. By the way, I work for Vodafone so if you still have problems after finding out you're in an area of strong signal coverage please let me know.