You should connect cable to tuner B. There is an issue with looping from A to B. B to A is fine.
If as you say there is an issue? I have had mine connected this way since new. What is this issue?? Please explain. When I want to see another program from another satellite, (from any satellite to any other), I go into the satellites respective Bouquet and press OK for whatever channel, and my dish moves to the channel on that satellite and 'hey presto' I can view it.
I completely agree with kevin1, but my dish is 20 metres away in the back garden and the cable going to the dish and motor is under ground through 1.5" pipe and sealed both ends, and its been there since 1990. Hence the single lnb.