Considering that so many Denon TU-1800 DAB tuners are being affected by this anoying problem right across the UK, and concidering that a full reset (or anything else for that matter) will not cure the problem, It is obvious that there is a serious malfunction within the DAB softwere dpt of this...
This is a common problem on the TU-1800 model, DENON's responce is that they simply do not want to know and have simply discontinued this model after a six year production run.
The fault lies within the TU-1800's dodgy microprocessor.
Legal action needed in this case to force Denon to address...