passdb backend = ldapsam:"ldap://127.0.0.1:389" will lead to error: smb_ldap_setup_connection: "ldap://127.0.0.1:389" ldap_initialize: Bad parameter to an ldap routine while passdb backend = ldapsam:ldap://127.0.0.1:389 works. At the same time multi-ldap-server setup must look like this: passdb backend = ldapsam:"ldap://ldap-1 ldap://ldap-2" This is way to inconsitent IMHO :-)
Fixed in SVN.