rem: return new OpenLayers.Pixel( Math.round(1/res * (lonlat.lon - extent.left)), Math.round(1/res * (extent.top - lonlat.lat)) ); 
add: var px = null; if (extent) { px = new OpenLayers.Pixel( Math.round(1/res * (lonlat.lon - extent.left)), Math.round(1/res * (extent.top - lonlat.lat))); } return px; 
context:     getOverviewPxFromLonLat: function(lonlat) {        var res  = this.ovmap.getResolution();        var extent = this.ovmap.getExtent();        return new OpenLayers.Pixel(                       Math.round(1/res * (lonlat.lon - extent.left)),                       Math.round(1/res * (extent.top - lonlat.lat))                       );    },
meta: 1027	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/1027/948406b5b534e857c903e75e0a9d75f05afb4cbd/OverviewMap.js/buggy/lib/OpenLayers/Control/OverviewMap.js