--- a/dwt/widgets/Combo.d	Wed Feb 06 11:08:01 2008 +0100
+++ b/dwt/widgets/Combo.d	Wed Feb 06 12:09:44 2008 +0100
@@ -77,7 +77,6 @@
     alias Composite.setBounds setBounds;
     alias Composite.setToolTipText setToolTipText;
 
-    alias extern(Windows) int function( HWND, uint, uint, int ) TWindowProc;
     private static Combo pThis;
     bool noSelection, ignoreDefaultSelection, ignoreCharacter, ignoreModify;
     HHOOK cbtHook;
@@ -110,15 +109,25 @@
      */
     static const int CBID_LIST = 1000;
     static const int CBID_EDIT = 1001;
-    static /*final*/ TWindowProc EditProc, ListProc;
+    static /*final*/ WNDPROC EditProc, ListProc;
 
-    static const TWindowProc ComboProc;
+    static /+const+/ WNDPROC ComboProc;
     static const TCHAR* ComboClass = "COMBOBOX\0";
 
-    static this() {
-        WNDCLASS lpWndClass;
-        OS.GetClassInfo (null, ComboClass, &lpWndClass);
-        ComboProc = lpWndClass.lpfnWndProc;
+    private static bool static_this_completed = false;
+    private static void static_this() {
+        if( static_this_completed ){
+            return;
+        }
+        synchronized {
+            if( static_this_completed ){
+                return;
+            }
+            WNDCLASS lpWndClass;
+            OS.GetClassInfo (null, ComboClass, &lpWndClass);
+            ComboProc = lpWndClass.lpfnWndProc;
+            static_this_completed = true;
+        }
     }
 
 
@@ -153,6 +162,7 @@
  * @see Widget#getStyle
  */
 public this (Composite parent, int style) {
+    static_this();
     super (parent, checkStyle (style));
     /* This code is intentionally commented */
     //if ((style & DWT.H_SCROLL) !is 0) this.style |= DWT.H_SCROLL;
@@ -527,11 +537,11 @@
     /* Get the text and list window procs */
     auto hwndText = OS.GetDlgItem (handle, CBID_EDIT);
     if (hwndText !is null && EditProc is null) {
-        EditProc = cast(TWindowProc) OS.GetWindowLong (hwndText, OS.GWL_WNDPROC);
+        EditProc = cast(WNDPROC) OS.GetWindowLong (hwndText, OS.GWL_WNDPROC);
     }
     auto hwndList = OS.GetDlgItem (handle, CBID_LIST);
     if (hwndList !is null && ListProc is null) {
-        ListProc = cast(TWindowProc) OS.GetWindowLong (hwndList, OS.GWL_WNDPROC);
+        ListProc = cast(WNDPROC) OS.GetWindowLong (hwndList, OS.GWL_WNDPROC);
     }
 
     /*