[Ticket Question] Help with a SD1 dialler

We have an 8 year old 4-channel SD1 unit in a holiday home in France that has recently stopped dialling out. The other functions (message record/test playback etc) appear to work. When you send a test call (put into ready & press A1 for instance) it immediately plays back the correct message over the internalspeaker 4x but does not appear to wait to detect the dialing tone, or phone out. The adjacent spurred 56V socket works with normal phone and 56V detected at SD1 phone input terminals i.e. probably not supply problem. From listening on the line it appears be trying to pulse dial (it used to tonedial) but forcing tone via phonenumber T-prefix makes no difference neither did introducing additional comma delays, or doing a factory reset & reprogram. It has worked fine for 8 years. I note adverts now selling European & French versions - has the phone system changed (property nr Nimes in Languedoc region) so that our existing unit is now obsolete there, or has the dialer component simply malfunctioned? Either way do I need a new unit and which version. Is there any advantage in getting the slightly more expensive remote reprogrammable equivalents (ie. what else do they do)& do you stock these?