URLLoader works only in one instance of the class

[nka1024]

hi, i made a class for connection with php-script, which handles sql-requests. it sends requests via URLLoader(), here is simplified code:

public class SQLWrapper extends MovieClip
{
    private var serverUrl:String = "http://192.168.177.128/";
    private var request:URLRequest;
    private var variables:URLVariables;
    private var loader:URLLoader;
    private var id:Number;  
    public  var object:Object;
    public  static const DATA_LOADED:String = "DATA_LOADED";
 
    public function SQLWrapper(_id:Number, _object:Object = null)   {
        object = _object;
        id = _id;
    }
 
    private function sndRequest():void {
        variables = new URLVariables();
        variables.id = id;
 
        request = new URLRequest();
        request.url = serverUrl;
        request.method = URLRequestMethod.GET;
        request.data = variables
 
        loader = new URLLoader();
        loader.addEventListener(Event.COMPLETE, rcv_hello);
        loader.load(request);   
    }
 
    private function rcvResponse(e:Event = null):void {
        loader.removeEventListener(Event.COMPLETE, dataLoaded);
 
        xml = XML(loader.data);
        sid = xml.children()[0].sid;
 
        trace(sid);
        dispatchEvent(new Event(SQLWrapper.DATA_LOADED));   
    }
}

it works fine, but when i create 2 instances of the class and call sndRequest() for each instance, URLLoader() sends only one request, but COMPLETE event triggers 2 times, so i get 2 trace(sid).
here is example of using instances. second instance created after triggering COMPELETE event in first URLLoader, but it still sends only one request

public class Main
{
    public function Main():void
    {       
        var market:Market = new Market();
        stage.addChild(market);
 
        getMarketItems(market);
    }
 
    private function getMarketItems(market:Object):void {
        var sql_a:SQLWrapper = new SQLWrapper(1, market);
        sql_a.addEventListener(SQLWrapper.RESPONSE, marketResponse);
        sql_a.sendRequest();
    }
 
    private function marketResponse(e:Event = null):void {
        var market:Market = Market(e.target.object);
        var item:MarketItem = new MarketItem();
 
        market.addItem(item);
        getItemStats(item);
    }
 
    private function getItemStats(item:Object):void {
        var sql_b:SQLWrapper = new SQLWrapper(2, item);
        sql_b.addEventListener(SQLWrapper.RESPONSE, itemResponse);
        sql_b.sendRequest();
    }
 
    private function itemResponse(e:Event = null):void {
        var item:MarketItem = MarketItem(e.target.xml.sid);
        item.addStat(sid);
    }
}

i'm new to as3, so i can't get why it happens. how can i make it work?

[nka1024]

found an answer on russian forum. it happens because responses being cached. solved by using random variable in GET-request. also can be solved by switching to POST method or setting URLRequest.cacheResponse to false