'Invalid call' error/exception from Reset

//-----------------------------------------------------------------------------// File: CreateDevice.cs//// Desc: This is the first tutorial for using Direct3D. In this tutorial, all//       we are doing is creating a Direct3D device and using it to clear the//       window.//// Copyright (c) Microsoft Corporation. All rights reserved.//-----------------------------------------------------------------------------using System;using System.Drawing;using System.Windows.Forms;using Microsoft.DirectX;using Microsoft.DirectX.Direct3D;namespace DeviceTutorial{	public class CreateDevice : Form	{		// Our global variables for this project		Device device = null; // Our rendering device		PresentParameters m_PresentParameters;		VertexBuffer m_VB = null;		public CreateDevice()		{			// Set the initial size of our form			this.ClientSize = new System.Drawing.Size(400,300);			// And it's caption			this.Text = "D3D Tutorial 01: CreateDevice";		}				public bool InitializeGraphics()		{			try			{				// Now let's setup our D3D stuff				m_PresentParameters = new PresentParameters();				m_PresentParameters.Windowed = true;				m_PresentParameters.SwapEffect = SwapEffect.Discard;				device = new Device(0, DeviceType.Hardware, this, CreateFlags.HardwareVertexProcessing, m_PresentParameters);				device.DeviceReset += new EventHandler(device_DeviceReset);				device.DeviceLost += new EventHandler(device_DeviceLost);				device_DeviceReset(this, null);				return true;			}			catch (DirectXException)            {                 return false;             }		}		void device_DeviceReset(object sender, EventArgs e)		{			if (m_VB == null)				m_VB = new VertexBuffer(typeof(Vector3), 8, device,										Usage.Dynamic | Usage.WriteOnly,										VertexFormats.Position, Pool.Default);		}		void device_DeviceLost(object sender, EventArgs e)		{			if (m_VB != null)			{				m_VB.Dispose();				m_VB = null;			}		}		private void Render()		{			if (device == null) 				return;			//Clear the backbuffer to a blue color 			device.Clear(ClearFlags.Target, System.Drawing.Color.Blue, 1.0f, 0);			//Begin the scene			device.BeginScene();						// Rendering of scene objects can happen here			//Vector3[] points = new Vector3[8];			////Lock vb			//GraphicsStream data = m_VB.Lock(0, 0, LockFlags.Discard);			//data.Write(points);			////Unlock vb			//m_VB.Unlock();    			//End the scene			device.EndScene();			try			{				device.Present();			}			catch (DeviceLostException)			{				for (int i = 0; i < 100000; i++)				{					int result;					device.CheckCooperativeLevel(out result);					if (result == (int)ResultCode.DeviceNotReset)					{						device.Reset(m_PresentParameters);						break;					}					System.Threading.Thread.Sleep(200);				}			}		}		protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)		{			this.Render(); // Render on painting		}		protected override void OnKeyPress(System.Windows.Forms.KeyPressEventArgs e)		{			if ((int)(byte)e.KeyChar == (int)System.Windows.Forms.Keys.Escape)				this.Close(); // Esc was pressed		}		/// <summary>		/// The main entry point for the application.		/// </summary>		static void Main() 		{            using (CreateDevice frm = new CreateDevice())            {                if (!frm.InitializeGraphics()) // Initialize Direct3D                {                    MessageBox.Show("Could not initialize Direct3D.  This tutorial will exit.");                    return;                }                frm.Show();                // While the form is still valid, render and process messages                while(frm.Created)                {                    frm.Render();                    Application.DoEvents();                }            }		}	}}