I've had a few tests off here and one from somewhere else and all seem to be the same problem, the op has sky sports 3 hd and sky sports f1 having issues, for me its mostly all of the channels on all tests I've had, I find some channels will work well for awile and then go off for a bit with scrambled on the screen then come back on, my internet reads 75 mb speeds and all other lines I have in the house are fine for sly. just the cable side of things suck.