Index: class/Managed.Windows.Forms/System.Windows.Forms/ControlPaint.cs
===================================================================
--- class/Managed.Windows.Forms/System.Windows.Forms/ControlPaint.cs	(revision 102320)
+++ class/Managed.Windows.Forms/System.Windows.Forms/ControlPaint.cs	(working copy)
@@ -417,7 +417,7 @@
 #endif		
 
 		public static void DrawMixedCheckBox(Graphics graphics, Rectangle rectangle, ButtonState state) {
-			DrawCheckBox(graphics, rectangle, state);
+			ThemeEngine.Current.CPDrawMixedCheckBox (graphics, rectangle, state);
 		}
 
 		public static void DrawMixedCheckBox(Graphics graphics, int x, int y, int width, int height, ButtonState state) {
Index: class/Managed.Windows.Forms/System.Windows.Forms/Theme.cs
===================================================================
--- class/Managed.Windows.Forms/System.Windows.Forms/Theme.cs	(revision 102320)
+++ class/Managed.Windows.Forms/System.Windows.Forms/Theme.cs	(working copy)
@@ -1021,6 +1021,7 @@
 		public abstract void CPDrawImageDisabled (Graphics graphics, Image image, int x, int y, Color background);
 		public abstract void CPDrawLockedFrame (Graphics graphics, Rectangle rectangle, bool primary);
 		public abstract void CPDrawMenuGlyph (Graphics graphics, Rectangle rectangle, MenuGlyph glyph, Color color, Color backColor);
+		public abstract void CPDrawMixedCheckBox (Graphics graphics, Rectangle rectangle, ButtonState state);
 		public abstract void CPDrawRadioButton (Graphics graphics, Rectangle rectangle, ButtonState state);
 		public abstract void CPDrawReversibleFrame (Rectangle rectangle, Color backColor, FrameStyle style);
 		public abstract void CPDrawReversibleLine (Point start, Point end, Color backColor);
Index: class/Managed.Windows.Forms/System.Windows.Forms/ThemeWin32Classic.cs
===================================================================
--- class/Managed.Windows.Forms/System.Windows.Forms/ThemeWin32Classic.cs	(revision 102320)
+++ class/Managed.Windows.Forms/System.Windows.Forms/ThemeWin32Classic.cs	(working copy)
@@ -6518,6 +6518,12 @@
 
 		}
 
+		[MonoTODO]
+		public override void CPDrawMixedCheckBox (Graphics graphics, Rectangle rectangle, ButtonState state)
+		{
+			CPDrawCheckBox (graphics, rectangle, state);
+		}
+
 		public override void CPDrawRadioButton (Graphics dc, Rectangle rectangle, ButtonState state)
 		{
 			CPColor cpcolor = ResPool.GetCPColor (ColorControl);