WMS getfeatureinfo() giving incorrect result

Question

I am using openlayers and Geoserver. I have created a base layer using OSM and then added wms layer topp:states. I want to show a world map and on that show US states. I have added onclick functionality to get feature info. However, when I click at any states, it gives incorrect state name or no result. This further worsens when I zoom in/zoom out or change the scale.Here is my code:

CSS:

#map {

            position: relative;
            height:1000px;
            width:1400px;

            float:left;
            margin:0px ;
        }

Script:

 var bounds = new OpenLayers.Bounds(
           -180,-90,0,90
        );

        format = 'image/png';

        var options = {
             controls: [],
            maxExtent: bounds,
            maxResolution: 0.22563114453125,
            projection: "EPSG:4326",
            units: 'degrees',
            displayProjection: new OpenLayers.Projection("EPSG:4326")

        };
        map = new OpenLayers.Map('map', options);
        layer = new OpenLayers.Layer.OSM("Base OpenStreet Map");
     states = new OpenLayers.Layer.WMS(
            "NA states", "http://localhost:8080/geoserver/wms",
            {
                layers: 'topp:states', styles: '', transparent: true,  format: 'image/png'
            },
            { isBaseLayer: false, singleTile: false,displayOutsideMaxExtent: true, ratio: 1,yx : {'EPSG:4326' : true} }
        );
       map.addLayers([layer,states]);

Code with call to getfeatureInfo:

       map.events.register('click', map, function (e) {
                            document.getElementById('nodelist').innerHTML =   "Loading... please wait...";
                            OpenLayers.Request.GET({url:"http://localhost:8080/geoserver/wms",params:{
                                REQUEST: "GetFeatureInfo",
                                EXCEPTIONS: "application/vnd.ogc.se_xml",
                                BBOX: bounds.toBBOX(),
                                 SERVICE: "WMS",
                                INFO_FORMAT: 'text/html',
                                QUERY_LAYERS: [ map.layers[1].params.LAYERS],
                                FEATURE_COUNT: 50,
                                Layers: [map.layers[1].params.LAYERS],
                                 WIDTH: map.size.w,
                                HEIGHT: map.size.h,
                                x: Math.floor(e.xy.x),
                                 y: Math.floor(e.xy.y),

                               }, success:setHTML});
                            OpenLayers.Event.stop(e);
                       });

It may have to do with bounds or extents,but that's just my guess.