C#

 private GraphicsPath m_gpExpandBox;     // Represents the box for the expand and contract

      public Node(string name)
      {
         // Set the name of this node
         m_name = name;

         // Create objects
         m_childNodes = new List<Node>();
----->   m_gpExpandBox = new GraphicsPath();
         m_gpTextBacking = new GraphicsPath();
         m_fontLocation = new Point(0, 0);

         // Set size and location of the node
         m_size = new Size(60, 20);
         m_location = new Point(0, 0);
      }

gwithey wrote:

Do you think this could be a cause of the problem even though it complains of an invalid perameter.

 public int Draw(Graphics g)
      {
         DrawNode();
        
         // Create font for text
         Font nodeFont = new Font(FontFamily.GenericSansSerif, 10f, FontStyle.Regular);

         // Fill node if selected
         if (m_selected)
         {
            g.FillPath(Brushes.Red, m_gpTextBacking);
            g.DrawString(m_name, nodeFont, Brushes.White, m_fontLocation);
         }
         else
         {
            g.DrawString(m_name, nodeFont, Brushes.Black, m_fontLocation);
         }
         
         // Draw node backing if hover is true
         if (m_hover)
         {
            g.DrawPath(Pens.Black, m_gpTextBacking);
         }

         // Draw expand box
         g.FillPath(Brushes.Gray, m_gpExpandBox);
         g.DrawPath(Pens.Black, m_gpExpandBox);

         // Dispose of graphics paths
------>  //m_gpExpandBox.Dispose();
------>  //m_gpTextBacking.Dispose();