1) two handsets show the same problem
3) landline from local cable company (Virgin Media)
4) broadband only via same line and is working normally
5) callers do not hear a prompt to leave message
Thank you for yoru suggestions. I had already tried toremove batteries from the handsets without results. However while writing to you and checking email my wife made an external phone call and after that the problem had disappeared. We checked and both handsets ring and the answering machine is back to normal. Still a mystery of what and why it happened. Anyway thank you very much for the advice offered.