I have a Humax set-top box (for BBC Prime) and Sony HDD/DVD Recorder and it works fine.
I have 2 SCARTS on the Humax Box - one marked for TV and one for VCR.
And 2 SCARTS on the DVD Recorder one marked Line 1 and the other Line 3/Decoder.
Under instructions from my DVD Recorder Manual:
Connect 'TV Scart' (Humax) with 'Line3' (DVD Recorder)
Connect 'Line1' (DVD Recorder) with one of the Scarts on my Samsung TV.
Hope that helps.
Just bought the DVD Recorder last week and must say it's great - no more need for VHS tapes ever again.
And more than enough space with 250GB to play with.