Index: Source/OpenTK/Platform/Windows/WinRawMouse.cs
===================================================================
--- Source/OpenTK/Platform/Windows/WinRawMouse.cs	(revision 3125)
+++ Source/OpenTK/Platform/Windows/WinRawMouse.cs	(working copy)
@@ -137,6 +137,8 @@
             }
         }
 
+        delegate void MouseButtonChangedHandler(MouseButton Button);
+
         public bool ProcessMouseEvent(RawInput rin)
         {
             RawMouse raw = rin.Data.Mouse;
@@ -158,17 +160,20 @@
             int mouse_handle = rawids.ContainsKey(handle) ? rawids[handle] : 0;
             mouse = mice[mouse_handle];
 
-            if ((raw.ButtonFlags & RawInputMouseState.LEFT_BUTTON_DOWN) != 0) mouse.EnableBit((int)MouseButton.Left);
-            if ((raw.ButtonFlags & RawInputMouseState.LEFT_BUTTON_UP) != 0) mouse.DisableBit((int)MouseButton.Left);
-            if ((raw.ButtonFlags & RawInputMouseState.RIGHT_BUTTON_DOWN) != 0) mouse.EnableBit((int)MouseButton.Right);
-            if ((raw.ButtonFlags & RawInputMouseState.RIGHT_BUTTON_UP) != 0) mouse.DisableBit((int)MouseButton.Right);
-            if ((raw.ButtonFlags & RawInputMouseState.MIDDLE_BUTTON_DOWN) != 0) mouse.EnableBit((int)MouseButton.Middle);
-            if ((raw.ButtonFlags & RawInputMouseState.MIDDLE_BUTTON_UP) != 0) mouse.DisableBit((int)MouseButton.Middle);
-            if ((raw.ButtonFlags & RawInputMouseState.BUTTON_4_DOWN) != 0) mouse.EnableBit((int)MouseButton.Button1);
-            if ((raw.ButtonFlags & RawInputMouseState.BUTTON_4_UP) != 0) mouse.DisableBit((int)MouseButton.Button1);
-            if ((raw.ButtonFlags & RawInputMouseState.BUTTON_5_DOWN) != 0) mouse.EnableBit((int)MouseButton.Button2);
-            if ((raw.ButtonFlags & RawInputMouseState.BUTTON_5_UP) != 0) mouse.DisableBit((int)MouseButton.Button2);
+            MouseButtonChangedHandler EnableBit = (Button) => { mouse.EnableBit((int)Button); Functions.SetCapture(Window); };
+            MouseButtonChangedHandler DisableBit = (Button) => { mouse.DisableBit((int)Button); Functions.ReleaseCapture(); };
 
+            if ((raw.ButtonFlags & RawInputMouseState.LEFT_BUTTON_DOWN) != 0) EnableBit(MouseButton.Left);
+            if ((raw.ButtonFlags & RawInputMouseState.LEFT_BUTTON_UP) != 0) DisableBit(MouseButton.Left);
+            if ((raw.ButtonFlags & RawInputMouseState.RIGHT_BUTTON_DOWN) != 0) EnableBit(MouseButton.Right);
+            if ((raw.ButtonFlags & RawInputMouseState.RIGHT_BUTTON_UP) != 0) DisableBit(MouseButton.Right);
+            if ((raw.ButtonFlags & RawInputMouseState.MIDDLE_BUTTON_DOWN) != 0) EnableBit(MouseButton.Middle);
+            if ((raw.ButtonFlags & RawInputMouseState.MIDDLE_BUTTON_UP) != 0) DisableBit(MouseButton.Middle);
+            if ((raw.ButtonFlags & RawInputMouseState.BUTTON_4_DOWN) != 0) EnableBit(MouseButton.Button1);
+            if ((raw.ButtonFlags & RawInputMouseState.BUTTON_4_UP) != 0) DisableBit(MouseButton.Button1);
+            if ((raw.ButtonFlags & RawInputMouseState.BUTTON_5_DOWN) != 0) EnableBit(MouseButton.Button2);
+            if ((raw.ButtonFlags & RawInputMouseState.BUTTON_5_UP) != 0) DisableBit(MouseButton.Button2);
+
             if ((raw.ButtonFlags & RawInputMouseState.WHEEL) != 0)
                 mouse.WheelPrecise += (short)raw.ButtonData / 120.0f;