WFS open layers, doesn't return a field result when called

Question

I've a problem when I call a WFS service, I want to select a file (its attributes) called "DICOFRE".

The service is OK in the institution that produces it, but in my institution when I call the service I have problems in that part of the code (and the code is same as the other institution code)...

Maybe I should change something in the code? If yes what am I doing wrong... if I'm calling the service to my organization and doesn't return the results of the field...

Code:

var wfsProtocol = new OpenLayers.Protocol.WFS.fromWMSLayer(layer_freg);
            var response = wfsProtocol.read({
                filter: pfilter,
                extractAttributes: true,
                infoFormat: "application/vnd.ogc.gml",
                //resultType: "hits",
                callback: function (resp) {
                    if (resp.features == null ||
                        !resp.features.length <= 0) {
                        alert("Não foi possivel gerar DICOFRE!");
                        //layer_editor.destroyFeatures(event.feature);
                        //return false;
                    }

Can somebody help please?