Points appear at different location when using google map overlay

Question

I have used vector point from database and also polygon country vectors from database.Points appear with in this country vectors but as I switch to google earth map as base layer the points at smaller zoom level would appear outside boundary where as at other zoom level it would appear inside. I have tried to add projection too but in vain.Do I need to reproject google earth's base layer and How?

map = new OpenLayers.Map('map', {
                    controls: [
                        new OpenLayers.Control.Navigation(),
                        new OpenLayers.Control.PanZoomBar(),
                        new OpenLayers.Control.LayerSwitcher({'ascending':false}),                       
                        new OpenLayers.Control.ScaleLine(),
                        new OpenLayers.Control.MousePosition(),
                        new OpenLayers.Control.OverviewMap(),
                        new OpenLayers.Control.KeyboardDefaults()
                    ],                 
             projection: new OpenLayers.Projection("EPSG:900913"),
             displayProjection: new OpenLayers.Projection("EPSG:4326"),
             numZoomLevels: 21,
             maxExtent: new OpenLayers.Bounds(-20037508, -20037508,20037508, 20037508.34)

                });           

                var border = new OpenLayers.Layer.WMS( "Border",
                url, 
                {layers: 'GisData:BORDER'}
            );

                var dsBand = new OpenLayers.Layer.WMS( "District Band",
                url, 
                {layers: 'GisData:BND'}
            );                  


                var Site1 = new OpenLayers.Layer.WMS( "Site 1",
                url, 
                {layers: 'GisData:sites', transparent: "true",format: "image/png"}             
            );
                dwnSite3G.setIsBaseLayer(false);

                var Site2 = new OpenLayers.Layer.WMS( "Site 2",
                url, 
                {layers: 'GisData:sites2', transparent: "true",format: "image/png"}             
            );


                var g_pmap = new OpenLayers.Layer.Google(
                "Google Physical",
                {type: G_PHYSICAL_MAP}
                );

                var gmap_gs = new OpenLayers.Layer.Google(
                    "Google Streets" // the default

                );

                var gmap_ghy  = new OpenLayers.Layer.Google(
                    "Google Hybrid",
                    {type: G_HYBRID_MAP}
                );

                var gmap_gsat = new OpenLayers.Layer.Google(
                    "Google Satellite",
                    {type: G_SATELLITE_MAP}
                )

Answer 1

Your map options are not correct. To use Google as a base layer you have to pass the following options:

var options = {
   projection: new OpenLayers.Projection("EPSG:900913"),
   displayProjection: new OpenLayers.Projection("EPSG:4326"),
   numZoomLevels: 21,
   maxExtent: new OpenLayers.Bounds(-20037508, -20037508,20037508, 20037508.34)
};
var map = new OpenLayers.Map(options);

and set

var googleStreets = new OpenLayers.Layer.Google(
            "Google Streets",
            {'sphericalMercator': true}
        );

on the Google Layers.

Documentation for using OpenLayers with a Spherical Mercator projection:

http://docs.openlayers.org/library/spherical_mercator.html

Answer 2

The projection for your layers is EPSG4326 and the one used by google is google mercator ESPG:900913. This might be leading to the changes in the projection system .