Index: win32ss/user/ntuser/nonclient.c
===================================================================
--- win32ss/user/ntuser/nonclient.c	(revision 73846)
+++ win32ss/user/ntuser/nonclient.c	(working copy)
@@ -1950,6 +1950,8 @@
             RECTL_vInflateRect(&rcWindow, -UserGetSystemMetrics(SM_CXDLGFRAME), -UserGetSystemMetrics(SM_CYDLGFRAME));
         else if (HAS_THINFRAME( Style, ExStyle ))
             RECTL_vInflateRect(&rcWindow, -UserGetSystemMetrics(SM_CXBORDER), -UserGetSystemMetrics(SM_CYBORDER));
+        else if (HAS_CLIENTFRAME( Style, ExStyle ))
+            RECTL_vInflateRect(&rcWindow, -UserGetSystemMetrics(SM_CXEDGE), -UserGetSystemMetrics(SM_CYEDGE));
         if (!RECTL_bPointInRect( &rcWindow, pt.x, pt.y  )) return HTBORDER;
     }
 
Index: win32ss/user/ntuser/window.h
===================================================================
--- win32ss/user/ntuser/window.h	(revision 73846)
+++ win32ss/user/ntuser/window.h	(working copy)
@@ -16,6 +16,9 @@
 #define HAS_THINFRAME(Style, ExStyle) \
             (((Style) & WS_BORDER) || (!((Style) & (WS_CHILD | WS_POPUP))))
 
+#define HAS_CLIENTFRAME(Style, ExStyle) \
+            (((ExStyle) & WS_EX_CLIENTEDGE) || (!((Style) & (WS_CHILD | WS_POPUP))))
+
 #define HAS_MENU(pWnd,style)  ((((style) & (WS_CHILD | WS_POPUP)) != WS_CHILD) && (pWnd->IDMenu) && IntIsMenu(UlongToHandle(pWnd->IDMenu)))
 
 #define IntIsDesktopWindow(WndObj) \