diff --git a/Fltk/GUI.cpp b/Fltk/GUI.cpp
index f2602e0125cefa4e1787347cbd1209e2bd277091..15263158fbb72ee2f26a3bd1ced116a5e793429c 100644
--- a/Fltk/GUI.cpp
+++ b/Fltk/GUI.cpp
@@ -70,7 +70,7 @@ GUI::GUI() {
 
   {
     int width = 152 ;
-    MH = 2*BH+6 ; // this is the initial width: no dynamic button is shown!
+    MH = 2*BH+6 ; // this is the initial height: no dynamic button is shown!
 
     m_window = new Fl_Window(width,MH);
     m_window->box(FL_THIN_UP_BOX);
@@ -225,7 +225,6 @@ void GUI::set_size(int w, int h){
 
 void GUI::set_menu_size(int nb_butt){
   m_window->size(m_window->w(), MH + nb_butt*BH);
-  m_window->redraw();
 }
 
 // The window for general options
diff --git a/Fltk/GUI.h b/Fltk/GUI.h
index b1c1c26c09bd92fe139d12e0202be4c689f48d16..f6a99475f7cbc8781dc3e27085bbadfbdb547ebd 100644
--- a/Fltk/GUI.h
+++ b/Fltk/GUI.h
@@ -45,8 +45,10 @@ public:
 
 class GUI{
 
-  int BH; // button height
-  int WB; // window border
+  int BH; // generic button height
+  int WB; // generic window border
+  int MH; // height of the unchangeable part of the menu window
+  // All other diemnsions are automatic, or governed by CTX
   
   // Windows
   Fl_Window  *m_window, *g_window, *gen_window, *geo_window ;
@@ -89,6 +91,7 @@ public:
   void draw_gl();
   void draw_gl_overlay();
   void set_size(int w, int h);
+  void set_menu_size(int nb_butt);
 
   void opt_general();
   void opt_geometry();