LOL, just realised you hijacked an old thread
hence the samsung comment.
The recorder you have I think has only an ANALOGUE tuner hence the BBC1, BBC2, ITV, C4 and there should be C5 though in the next few years even these will vanish...
To record Sky (from a skybox) or VM from a VM box you have to select the AV/scart input (should be in manual) and/or if available use the analogue passthrough (VM is phasing this out)
You can only record whichever channel you have your sky/VM box on at that time (though you can set the boxes to change channel on the timer automatically)