I think this is a bugfix that somehow was dropped from the 3.0 tree.

source/lib/smbldap.c

@@ -428,6 +428,8 @@ BOOL fetch_ldap_pw(char **dn, char** pw)
 		/* Believe it or not, but LDAP will deny a delete and
 		   an add at the same time if the values are the
 		   same... */
+
+		ldap_value_free(values);
 		return;
 	}