Our Sony Bravia TV signal keeps losing signal for periods of upto 2 minutes with the “selected programme is not tuned” error message appearing each time. Upon checking on System information the signal quality drops to 0 when the error appears and the screen goes black. During the time when signal drops off and is watchable the signal strength remains at 51 throughout. This problem does not seem to occur on the HD channels where both the signal strength and quality are both high. We have tried retuning the tv and have replaced aerials and aerial cables. This same problem does not affect other TVs in the household by other manufacturers and only seems to affect Sony products. Any ideas?