Followup post:
It turns out the new Samsung Sky+ HD box I bought WAS faulty. I went through the power-up sequence with the Ebay vendor while he was on the phone, and it wouldn't boot whatever I did.
It was decided that I return the box for a replacement, and was confirmed faulty. Although I had to pay the return carriage, the vendor sent me a Quad LNB (which I do need) with the replacement box as some consolation.
I think that was pretty good service, and I got him to check the new box before he sent it out, and when it arrived it does indeed work with only one input. I'm still getting estimates for the new LNB installation... (cheapest so far £225: it's a non-standard inst. high roof job)
To save starting another thread, can I ask about something else? I'm using the HD box set to 1080i though HDMI. I have the Toshiba TV resolution on 1080p and "Exact Scan" setting. On HD programmes, and wide-screen SD programmes, the aspect ratio is completely fine as expected. On SD channels though like G.O.L.D, Virgin1 and all the other ones that originate older programming only in regular 4:3 aspect ratio, the picture is stretched to 16:9 even so, which I hate.
Previously I used my standard Sky box set to 16:9 via SCART feeding into my Panasonic DVD/PVR, and had the Panny feeding into the TV via its HDMI at 1080p/Exact Scan. With this arrangement watching those channels, the aspect ratio changed automatically (most of the time) when the broadcast went from 4:3 to 16:9 (as during adverts etc).
Can the Samsung Sky HD Box not do the same thing? Do I have to watch all upscaled 4:3 programming stretched out to 16:9? Pumpkin-faces I call it?
Dave