win32ss/user/ntuser/winpos.c | 28 ++++++++--------------------
 2 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/win32ss/user/ntuser/winpos.c b/win32ss/user/ntuser/winpos.c
index bbe6ac5f90..0cee27b560 100644
--- a/win32ss/user/ntuser/winpos.c
+++ b/win32ss/user/ntuser/winpos.c
@@ -2112,25 +2112,13 @@ co_WinPosSetWindowPos(
 
                     if ( !(pwnd->style & WS_CHILD) )
                     {
-                        /*
-                         * Check if we have these specific windows style bits set/reset.
-                         * FIXME: There may be other combinations of styles that need this handling as well.
-                         * This fixes the ReactOS Calculator buttons disappearing in CORE-16827.
-                         */
-                        if ((Window->style & WS_CLIPSIBLINGS) && !(Window->style & (WS_POPUP | WS_CLIPCHILDREN | WS_SIZEBOX)))
-                        {
-                            IntSendNCPaint(pwnd, HRGN_WINDOW); // Paint the whole frame.
-                        }
-                        else  // Use region handling
-                        {
-                            HRGN DcRgn = NtGdiCreateRectRgn(0, 0, 0, 0);
-                            PREGION DcRgnObj = REGION_LockRgn(DcRgn);
-                            TRACE("SWP_FRAMECHANGED win %p hRgn %p\n",pwnd, DcRgn);
-                            IntGdiCombineRgn(DcRgnObj, VisBefore, NULL, RGN_COPY);
-                            REGION_UnlockRgn(DcRgnObj);
-                            ForceNCPaintErase(pwnd, DcRgn, DcRgnObj);
-                            GreDeleteObject(DcRgn);
-                        }
+                        HRGN DcRgn = NtGdiCreateRectRgn(0, 0, 0, 0);
+                        PREGION DcRgnObj = REGION_LockRgn(DcRgn);
+                        TRACE("SWP_FRAMECHANGED win %p hRgn %p\n",pwnd, DcRgn);
+                        IntGdiCombineRgn(DcRgnObj, VisBefore, NULL, RGN_COPY);
+                        REGION_UnlockRgn(DcRgnObj);
+                        ForceNCPaintErase(pwnd, DcRgn, DcRgnObj);
+                        GreDeleteObject(DcRgn);                      
                     }
                 }
              }

diff --git a/win32ss/user/ntuser/painting.c b/win32ss/user/ntuser/painting.c
index eb2815c644..1a96550a27 100644
--- a/win32ss/user/ntuser/painting.c
+++ b/win32ss/user/ntuser/painting.c
@@ -300,7 +300,7 @@ IntGetNCUpdateRgn(PWND Window, BOOL Validate)
          GreDeleteObject(hRgnWindow);
          GreDeleteObject(hRgnNonClient);
          Window->state &= ~WNDS_UPDATEDIRTY;
-         return NULL;
+         return HRGN_WINDOW;
       }
 
       /*