The old version of the data was missing some channel offset data.
On C21 and C60, Ofcom notes that less stringent out-of-band emissions limits apply to low power (less than 100 watts ERP) transmitters than for higher power transmitters on those channels. The broadcasters use band-edge offsets primarily as a means of meeting emissions limits and they are not actually employed to protect DTT reception from neighbouring services. As a rule of thumb, low power transmitters which switched to digital early in the switchover process tended to have offsets implemented on band-edge channels, while those switching later did not.
MikeB: Many thanks for your help! I haven't a manual but no doubt will find one somewhere on the net! Managed to re-tune my other old SAMSUNG TV (including FILM 4) from the MENU very easily! The actual MENU on this one doesn't have any 'set up' 're-set' 'tune' or 're-tune'.....So I'm still at the GGGGRRRRRRR! stage.......
jacquicousins: Although a form or reset can be achieved on some of the older Samsung's by pressing and holding down (for about 15 secs) the exit button on the remote control, your model would appear to be a later and even less user friendly version than the original models.
You should try entering the "plug and play" menu again by selecting "menu" then "system", should this result in "plug and play" being seen then select it, if though you want to ensure that the tuners memory is completely wiped out before the P&P auto-tune starts then remove the aerial prior to this taking place, then once that it has and which will likely result in a "no channels stored" or similar message being seen, reconnect the aerial and then repeat the procedure.
It would also be of assistance if the model number of the device in question was known.