Well, yes, we are using version 1.0 and, yes, he was old enough (some 60-70 years old)... Now, since we have v1.0 we cannot (and I guess we'll never be able to) know who have died "regularly" (Keopi or Hoani) and who has disappeared, since we cannot clik on the tombstones to know the name of the buried ones...
Anyway, we are glad to understand that this is caused by a bug rather than a human error (!!!).
Thanks for your help,