Webservice calls in queue: problem on Android

I hope someone can help me, I have a queue for webservice calls and it works perfectly in Windows Phone and iOS, but not on Android.
I can't get a response from Android.
Here is my code (usage HTTPRequestQueue.AddToQueue(yourUrl) )

public class HTTPRequestQueue
{
public class QueueRequest
{
public string Url;
public Action Callback;
public string Id;

        public QueueRequest(string url, Action<WebRequestCompletedArgs> callback)
        {
            Url = url;
            Callback = callback;
        }
    }

    enum QueueStatus { Stopped, OnGoing }; // Queue can be in one of these states

    public List<QueueRequest> requests = new List<QueueRequest>();


    QueueStatus currentStatus;
    QueueRequest currentRequest;
    HttpWebRequest WebRequest;

    public HTTPRequestQueue()
    {
        currentStatus = QueueStatus.Stopped;
        WebRequest = null;
    }

    public void AddToQueue(string url, Action<WebRequestCompletedArgs> callback)
    {

        requests.Add(new QueueRequest(url, callback));
        MakeNextRequest();
    }

    public void Start()
    {
        MakeNextRequest();
    }

    public void StopQueue()
    {
        if (currentStatus == QueueStatus.OnGoing)
        {
            currentStatus = QueueStatus.Stopped;
            if (WebRequest != null)
                WebRequest.Abort();
            requests.Insert(0, currentRequest);

        }
    }

    //Private functions 
    void MakeNextRequest()
    {

        if (currentStatus == QueueStatus.OnGoing)
        {

            if (requests.Count() == 0)
            {
                currentStatus = QueueStatus.Stopped;
            }
            else if (requests.Count() > 0 && WebRequest == null)
            {
                MakeRequest();
            }

        }
        else if (currentStatus == QueueStatus.Stopped)
        {
            if (requests.Count() > 0 && WebRequest == null)
            {
                currentStatus = QueueStatus.OnGoing;
                MakeRequest();
            }
        }
    }

    void MakeRequest()
    {
        if (currentStatus == QueueStatus.Stopped)
            return;

        currentRequest = requests.First();

        try
        {
            WebRequest = (HttpWebRequest)HttpWebRequest.Create(currentRequest.Url);
            WebRequest.BeginGetResponse(new AsyncCallback(FinishWebRequest), this);
        }
        catch (WebException ex)
        {
            WebRequest = null;
            if (currentRequest.Callback != null)
            {
                currentRequest.Callback(new WebRequestCompletedArgs(WebRequestStatus.WebException));
            }
        }
        catch
        {
            if (currentRequest.Callback != null)
            {
                currentRequest.Callback(new WebRequestCompletedArgs(WebRequestStatus.BeginWebRequestGeneralError));
            }
        }
        //
        if (WebRequest != null)
        {
            if (requests.Count > 0)
                requests.RemoveAt(0);
        }
    }

    void RequestCompleted(QueueRequest request, string responseString)
    {
        if (request.Callback != null)
        {
            request.Callback(new WebRequestCompletedArgs(responseString));
        }
    }

    void FinishWebRequest(IAsyncResult result)
    {
        HTTPRequestQueue ptr = (HTTPRequestQueue)result.AsyncState;

        if (currentStatus == QueueStatus.Stopped)
        {
            ptr.WebRequest = null; //Queue is been stopped 
            return;
        }

        HttpWebRequest request = (HttpWebRequest)ptr.WebRequest;
        HttpWebResponse response = null;
        Stream streamResponse = null;
        StreamReader streamRead = null;
        WebRequestStatus status = WebRequestStatus.Completed;

        bool requestSuccess = true;

        try
        {
            // End the operation
            response = (HttpWebResponse)request.EndGetResponse(result);
            streamResponse = response.GetResponseStream();
            streamRead = new StreamReader(streamResponse);
            string responseString = streamRead.ReadToEnd();
            RequestCompleted(currentRequest, responseString); //Request completed succesfully

        }
        catch (WebException e)
        {
            requestSuccess = false;
            status = WebRequestStatus.WebException;
        }
        catch (Exception ex)
        {
            requestSuccess = false;
            status = WebRequestStatus.FinishWebRequestGeneralError;
        }
        finally
        {
            // Close stream objects
            if (streamResponse != null)
                streamResponse.Dispose();
            if (streamRead != null)
                streamRead.Dispose();
            if (response != null)
                response.Dispose();

            ptr.WebRequest = null;

            if (requestSuccess)
                MakeNextRequest();
            else
            {
                if (currentRequest.Callback != null)
                {
                    currentRequest.Callback(new WebRequestCompletedArgs(status));
                }
            }
        }
    }

}