Re: ntl d5100
 

Just a note re this post. I've just had the same problem - not being able to register a handset. I discovered by trial and error that if you already have 5 handsets registered to the base it won't allow you to register another without deleting one of the others. You will notice this by the fact when you press and hold the page button you only get one beep. If less than 5 handsets are already registered you get 2 short beeps. Hope this is of some help.