add: if (debuggers.length < 1) return; ddd("findDebugger among "+debuggers.length+"\n"); 
context:     findDebugger: function(frame)    {        var win = getFrameWindow(frame);        if (!win)            return;        for (var i = 0; i < debuggers.length; ++i)        {            try            {                var debuggr = debuggers[i];                if (debuggr.supportsWindow(win))                    return debuggr;            }            catch (exc) {  ERROR("firebug-service findDebugger: "+exc);}        }    },
meta: 7450	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/7450/657c1059e813834f821277cbe0ed6b432bead8b9/firebug-service.js/buggy/extension/components/firebug-service.js