I've done a bit more investigation and it "seems" to be a connection issue. When my mum comes in and hoovers my room and moves the computer tower or if I accidentally move the cable with my foot then the connection will drop. Weird thing is though, I can get the connection back by unplugging my cable box downstairs and then turning it back on again - I would have thought that if it was the cable then I'd need to fiddle around with it rather than just going downstairs.