Winforms PictureBox.Load / LoadAsync don't work

I am trying to write a simple winform app that gets an xml file with image urls and shows the images: Here is an xml:

<catalog>
     <product>
          <imageurl>http://ift.tt/1DmECW9;
     <product>
     <product>
      ...
     <product>
</catalog>

I'm using a backgroung worker for this taks so my code looks like this:

private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
     XmlNodeList xnList = doc.SelectNodes(...);
     foreach (XmlNode product in xnList)
     {
          PictureBox img = new PictureBox();
          img.Dock = System.Windows.Forms.DockStyle.Fill;
          img.Location = new System.Drawing.Point(3, 28);
          img.Size = new System.Drawing.Size(194, 94);
          img.SizeMode = System.Windows.Forms.PictureBoxSizeMode.Zoom;

          //img.LoadAsync(product[...].InnerText);

          img.Load(product[...].InnerText);
     }
 }

When I use the img.LoadAsync I don't see any image and when I'm getting up to image number 1990 out of 8700 and the I'm getting this exception:

An exception of type 'System.ComponentModel.Win32Exception' occurred in 
System.Windows.Forms.dll but was not handled in user code

Additional information: Error creating window handle.

When I'm using img.Load I sometimes get the image and sometimes I get timeout exception...

This is not a difficult task to do and yet, how can I have a simple code that works ?