Following your advice, I change valor_combos method this way:

SELECT("v_clientes_")
cbo1= v_clientes_.loteamento && value of combo Loteamento stored in table
cbo2= v_clientes_.quadra && value of combo Quadra stored in table
WITH THISFORM
.cboQuadra.ROWSOURCETYPE = 3
.cboQuadra.REQUERY()
.cboLote.ROWSOURCETYPE = 3
.cboLote.REQUERY()
ENDWITH

codigo is my bound column, and is character type, ("2", "3", "45"....),

The field value of control source also match exactly the field value of the combobox:
cboLoteamento.ControSource = v_clientes_.loteamento
cboQuadra.ControSource = v_clientes_.quadra
cboLote.ControlSource = v_clientes_.lote

Sometimes there's a strange behavior, moving the pointer, sometimes the values
of the combos dissapear(2° e 3°combo), always the same in the records.

What could it be ?

TIA

Peter