A simple rule of thumb for signal strength is can you get a watchable picture on channel 5 on analogue? If not then there is insufficient signal strength provided by the antenna for digital heaven, probably you will need a higher gain aerial as digital signals are lower in strength than the 4 main analogue but roughly the same as channel 5. (or as busha says, a re-alignment might improve it) As for the reprogramming mine never did that except when a new channel became available (I don't use terrestrial any more I use freesat) so turn it off at the MAINS plug every night and you shouldn't have any more problems. The main channels don't change so tell it to bog off if it says it's found new channels and would you like to install them.