Be aware that isolation devices can introduce little gremlins that will mess with some channels if you have digital cable. I had a Time-Warner tech come out when I first moved in because I wasn't getting several channels that I should have been - he isolated the problem as the Mondial Magic I had in line between the cable outlet and my cable box (which is connected to my DAC via toslink).
I felt pretty stupid, but then again, was totally unaware that those isolation boxes can cause such problems with the newer digital TV boxes (was a non-issue with the older, non-digital boxes I'd had in the past).