You can not connect psql even with th right password

PostgreSQL supports various user authentication modes :

 trust : password is ignored
 md5 : password is prompted and sent encrypted to the server
 ldap|pam|.... : other authentication modes
 ident sameuser : Connections are accepted only if the host user name matches the postgres user name.

When this last mode is used, Saada can never connect the db with another user name than the host one. This mode must then be changed in the file pg_hba.conf where the line # "local" is for Unix domain socket connections only local all all ident sameuser must be replaced with # "local" is for Unix domain socket connections only local all all md5 (or any other mode)