My new Toshiba DVR20KB Freeview DVD/Video cassette recorder does not find DVB channels. We have checked that it is wired in correctly (coaxial cable goes from aerial to Toshiba, Toshiba to TV; scart cable from Toshiba to TV). We also checked the aerial cable by attaching it to a digital TV and it seems fine. But each time we run channel tuning it quickly runs through UHF channels and then reports finished, having found none. Otherwise the unit seems to work fine. Is it a dud to be replaced or is there something we're missing?