diff -ur pnetlib/System.Drawing/Toolkit/IToolkitWindowBuffer.cs pnetlib.new/System.Drawing/Toolkit/IToolkitWindowBuffer.cs
--- pnetlib/System.Drawing/Toolkit/IToolkitWindowBuffer.cs	2004-01-19 00:03:16.000000000 +0100
+++ pnetlib.new/System.Drawing/Toolkit/IToolkitWindowBuffer.cs	2005-09-08 14:13:02.065566875 +0200
@@ -29,8 +29,8 @@
 	public interface IToolkitWindowBuffer : IDisposable
 	{
 		// Return a buffer toolkit graphics to do the cached drawing.
-		IToolkitGraphics BeginDoubleBuffer();
+		IToolkitGraphics BeginDoubleBuffer(Rectangle r);
 		// Write the cache to the screen and dispose the toolkit graphics.
 		void EndDoubleBuffer();
 	}
-}
\ No newline at end of file
+}
diff -ur pnetlib/System.Drawing.Win32/DrawingWindowBuffer.cs pnetlib.new/System.Drawing.Win32/DrawingWindowBuffer.cs
--- pnetlib/System.Drawing.Win32/DrawingWindowBuffer.cs	2004-01-19 02:53:46.000000000 +0100
+++ pnetlib.new/System.Drawing.Win32/DrawingWindowBuffer.cs	2005-09-08 14:22:01.628293606 +0200
@@ -51,7 +51,7 @@
 				
 		}
 
-		public IToolkitGraphics BeginDoubleBuffer()
+		public IToolkitGraphics BeginDoubleBuffer(System.Drawing.Rectangle r)
 		{
 			Size newSize = (window as IToolkitWindow).Dimensions.Size;
 			// If the size changes, we need to recreate the buffer.
@@ -93,4 +93,4 @@
 		}
 
 	}
-}
\ No newline at end of file
+}
diff -ur pnetlib/System.Drawing.Xsharp/DrawingWindowBuffer.cs pnetlib.new/System.Drawing.Xsharp/DrawingWindowBuffer.cs
--- pnetlib/System.Drawing.Xsharp/DrawingWindowBuffer.cs	2004-01-24 02:16:21.000000000 +0100
+++ pnetlib.new/System.Drawing.Xsharp/DrawingWindowBuffer.cs	2005-09-08 14:20:35.020289314 +0200
@@ -64,7 +64,7 @@
 			}
 
 	// Begin a double buffer operation.
-	public IToolkitGraphics BeginDoubleBuffer()
+	public IToolkitGraphics BeginDoubleBuffer(System.Drawing.Rectangle r)
 			{
 				// Create the double buffer if necessary.
 				if(buffer == null)
@@ -72,6 +72,9 @@
 					CreateBuffer(widget.Width, widget.Height);
 				}
 
+				Xsharp.Rectangle rect = new Xsharp.Rectangle (r.X, r.Y, r.Width, r.Height);
+				buffer.SetClipRectangle (rect);
+
 				// Create a graphics object for the buffer and return it.
 				graphics = new DrawingGraphics
 					(toolkit, new Xsharp.Graphics(buffer));
diff -ur pnetlib/System.Windows.Forms/Control.cs pnetlib.new/System.Windows.Forms/Control.cs
--- pnetlib/System.Windows.Forms/Control.cs	2005-09-01 09:25:57.000000000 +0200
+++ pnetlib.new/System.Windows.Forms/Control.cs	2005-09-08 15:27:27.979669066 +0200
@@ -5938,7 +5938,8 @@
 				{
 					Graphics gFull = null;
 					Graphics g = null;
-					IToolkitGraphics toolkitGraphics = buffer.BeginDoubleBuffer();
+					IToolkitGraphics toolkitGraphics = buffer.BeginDoubleBuffer(clipBounds);
+					toolkitGraphics.SetClipRect (clipBounds.X, clipBounds.Y, clipBounds.Width, clipBounds.Height);
 					try
 					{
 						if (borderStyle != BorderStyle.None)
@@ -5948,6 +5949,7 @@
 						}
 					
 						g = ToolkitManager.CreateGraphics(toolkitGraphics, clientRectangle);
+						g.SetClip (clipBounds);
 
 						PaintEventArgs e = new PaintEventArgs(g, clipBounds);
 						if (GetStyle(ControlStyles.AllPaintingInWmPaint))
diff -ur pnetlib/Xsharp/DoubleBuffer.cs pnetlib.new/Xsharp/DoubleBuffer.cs
--- pnetlib/Xsharp/DoubleBuffer.cs	2005-03-10 18:30:02.000000000 +0100
+++ pnetlib.new/Xsharp/DoubleBuffer.cs	2005-09-08 15:49:26.588645650 +0200
@@ -39,6 +39,7 @@
 	// Internal state.
 	private InputOutputWidget widget;
 	private bool usesXdbe;
+	private Rectangle clipRect;
 
 	/// <summary>
 	/// <para>Constructs a new <see cref="T:Xsharp.DoubleBuffer"/>
@@ -60,6 +61,7 @@
 				this.widget = widget;
 				this.width = widget.width;
 				this.height = widget.height;
+				this.clipRect = new Rectangle (0, 0, widget.width, widget.height);
 				try
 				{
 					IntPtr display = dpy.Lock();
@@ -169,6 +171,11 @@
 				}
 			}
 
+	public void SetClipRectangle (Rectangle r)
+			{
+				clipRect = r;
+			}
+
 	// Start a double buffer drawing operation.
 	internal void Start(Graphics graphics)
 			{
@@ -231,21 +238,34 @@
 					IntPtr display = dpy.Lock();
 					if(handle != XDrawable.Zero)
 					{
-						if(usesXdbe)
+						using(Graphics g = new Graphics(widget))
 						{
-							Xlib.XdbeSwapInfo info = new Xlib.XdbeSwapInfo();
-							info.swap_window = widget.GetWidgetHandle();
-							info.swap_action = Xlib.XdbeSwapAction.Background;
-							Xlib.XdbeSwapBuffers(display, ref info, 1);
-						}
-						else
-						{
-							using(Graphics g = new Graphics(widget))
+							if(usesXdbe)
+							{
+								Xlib.XdbeSwapInfo info = new Xlib.XdbeSwapInfo();
+								info.swap_window = widget.GetWidgetHandle();
+								info.swap_action = Xlib.XdbeSwapAction.Background;
+								Xlib.XdbeSwapBuffers(display, ref info, 1);
+
+								// Copy the new front buffer back to the back
+								// buffer (needed for clipping).
+								Xlib.XCopyArea
+									(display, 
+									 widget.GetGCHandle(), handle, g.gc,
+									 0, 0,
+									 (uint)widget.width, (uint)widget.height,
+									 0, 0);
+							}
+							else
 							{
+								// Copy only the unclipped part of the buffer
+								// to the screen.
 								Xlib.XCopyArea
 									(display, handle,
-									 widget.GetGCHandle(), g.gc, 0, 0,
-									 (uint)width, (uint)height, 0, 0);
+									 widget.GetGCHandle(), g.gc,
+									 clipRect.x, clipRect.y,
+									 (uint)clipRect.width, (uint)clipRect.height,
+									 clipRect.x, clipRect.y);
 							}
 						}
 					}