I defined a replication between 1-2 group and the central group. This replication works just fine.
I also defined a replication between 3 and 4 . This replication also works fine. But when I insert a new record in 1-2, this is replicated to the central pc (3) but cannot be found in pc 4 (although the replication between 3 and 4 works perfect). It looks like when a change occurs in 3 that comes from the replication with (1-2) it isn't seen by the replication with 4.