Optimizer Directive on VB6 DLL

Hi , we have a VB6 DDL that execute some query on Informix IDS 9.40UC4 on Solaris 8 System. When we try to exec a select query that use a optimizer directive we got a syntiax error, any idea ?? We connet client machine using OLE DB provider shipped by INFORMIX client 2.50 TC3. Query is : SELECT --+ORDERED DISTINCT(tcatlgsut.num_supporto), 'T05012/' || evl.cod id_teca, evl.titolo, DATE('12/01/2005') data_trasm, substr(evl.trasm_ora,1, 2) || ':' || substr (evl.trasm_ora, 3, 2) ora, tcatlgcan.descr canale, evl.uorg, ' ' matricola, DATE('12/01/2005') data_prod, 'EVN' origine, tcatlgort.titolo AS titoloOR, substr(tcatlgort.ora_inizio,1, 2) || ':' || substr (tcatlgort.ora_inizio, 4, 2) AS oraOR FROM TCATLGEVL evl, tcatlgcan, OUTER (tcatlgsut) , OUTER (tcatlgort) WHERE tcatlgsut.id_teca = 'T05012/' || evl.cod AND tcatlgort.id_teca = 'T05012/' || evl.cod AND tcatlgcan.cod_canale = evl.canale AND canale =81 ORDER BY 1 desc, 2 thanks in advance !! Bye