diff --git a/src/render/Render_alternate.cpp b/src/render/Render_alternate.cpp
index 438612e7816ace1db6e2623a4e3305f0afbfaa3f..030d273a5b377f16d6ad496e4135d86b1a36e6ea 100644
--- a/src/render/Render_alternate.cpp
+++ b/src/render/Render_alternate.cpp
@@ -44,7 +44,6 @@
  *\file Render_alternate.cpp
  */
 
-
 #include "common/common.hpp"
 #include "common/Info.hpp"
 #include "common/Message.hpp"
@@ -172,7 +171,11 @@ void  Render_alternate::resizeGL(int width, int height) {
 
 }
 
+
 void  Render_alternate::paintGL(){
+    /*Do not call paintGL before rendering the trace*/
+    if(DRAWING_STATE_WAITING == _state)
+        return;
 
     //glClearColor(0.0, 1.0, 0.0, 1.0);
     resizeGL(Render_alternate::QGLWidget::width(), Render_alternate::QGLWidget::height());
@@ -193,9 +196,6 @@ void  Render_alternate::paintGL(){
     glDrawArrays(GL_QUADS, 0, 8);
     glDrawArrays(GL_LINES, 8, _ruler.getNbVertex());
     _ruler.unlock();
-
-
-
     /* drawing containers*/
     _containers.lock();
     //_modelview = glm::translate(_modelview, glm::vec3(0.0f, _ruler_y + _ruler_height -_y_state_translate,  _z_container));
@@ -245,6 +245,7 @@ void  Render_alternate::paintGL(){
         //restore matrix
         _modelview = tmp;
     }
+
     /*draw selection if necessary*/
     if (_mouse_pressed && (Info::Render::_key_ctrl == false) && !_mouse_pressed_inside_container){
         Element_pos x0, x1, y0, y1;
@@ -268,7 +269,7 @@ void  Render_alternate::paintGL(){
         glDisableVertexAttribArray(0);
         glDisableVertexAttribArray(1);
         _modelview = tmp;
-    }
+ }
 
     //    _containers.display(_modelview);
     //rendu
@@ -314,16 +315,16 @@ void  Render_alternate::paintGL(){
             if (it==it_end || render_to_screen_y(trace_to_render_y(_texts[i].y)) - render_to_screen_y(trace_to_render_y((*it).second))> height ){
                 const QString text_elided = metric.elidedText(_texts[i].value.c_str(), Qt::ElideRight, _x_scale_container_state*Info::Screen::width/(Info::Trace::depth+1.));
                 renderText ( render_to_screen_x(_texts[i].x * _x_scale_container_state/0.20),
-                         render_to_screen_y( trace_to_render_y(_texts[i].y) + 0.5),
-                         text_elided,
-                         arial_font);
+                             render_to_screen_y( trace_to_render_y(_texts[i].y) + 0.5),
+                             text_elided,
+                             arial_font);
 
-            //push only displayed values in the map
+                //push only displayed values in the map
                 previous_by_column[_texts[i].x]=_texts[i].y;
                 //displayed++;
             }//else{skipped++;}
         }
-        /* Draw ruler text */
+
         std::ostringstream buf_txt;
         Element_pos graduation_diff;
         Element_pos coeff_prefix;
@@ -371,9 +372,7 @@ void  Render_alternate::paintGL(){
                         buf_txt.str().c_str(),
                         arial_font);
 
-        }
-
-       
+    }
 
 
 //     Render_alternate::QGLWidget::setFocus(Qt::ActiveWindowFocusReason);/* give the focus to the render area for mouse and keyboard events */
@@ -754,14 +753,14 @@ GLuint Render_alternate::draw_wait() {
 void Render_alternate::call_ruler(){
     _ruler.setNbVertex(0);
     Element_pos graduation_diff;
-    Element_pos coeff_prefix;
+    //Element_pos coeff_prefix;
     const Element_pos offset_x = _default_entity_x_translate;
     const Element_pos offset_y = _ruler_y + _ruler_height+3.5;
 
     update_visible_interval_value();
 
     graduation_diff = Ruler::get_graduation_diff(Info::Render::_x_min_visible, Info::Render::_x_max_visible);
-    coeff_prefix    = Ruler::get_coeff_for_common_prefix(Info::Render::_x_min_visible, Info::Render::_x_max_visible);
+    //coeff_prefix    = Ruler::get_coeff_for_common_prefix(Info::Render::_x_min_visible, Info::Render::_x_max_visible);
     //draw quads
     set_color(0.0, 0.0, 1.0);
     _ruler.add(trace_to_render_x(Info::Render::_x_min_visible), 0, _r, _g, _b);
@@ -788,7 +787,7 @@ void Render_alternate::call_ruler(){
                    trace_to_render_x(i) + offset_x, 4+offset_y, _z_ruler);
     }
 
-    return;
+     return;
 }
 
 
@@ -1035,7 +1034,7 @@ void Render_alternate::start_ruler(){
 
 void Render_alternate::end_ruler(){
     _draw_ruler = false;
-    std::cout << "end_ruler" << std::endl;
+    //std::cout << "end_ruler" << std::endl;
 }
 
 void Render_alternate::end_draw(){
diff --git a/src/render/vbo.cpp b/src/render/vbo.cpp
index b6581feaa026ab049b87ce670727edbbc4c8ba7e..d7fecea27a8e99ba611fc8900995512ffa7e5a71 100644
--- a/src/render/vbo.cpp
+++ b/src/render/vbo.cpp
@@ -158,10 +158,7 @@ int Vbo::get_remaining_size() const{
 }
 
  void Vbo::config(){
-     std::cout << "Configuration du vbo, " << _nbVertex << " vertices" << std::endl;
      int vertex_size = _vertex.size() * sizeof(Element_pos);
-     std::cout << _vertex.size() << std::endl;
-     std::cout << _colors.size() << std::endl;
      int colors_size = _colors.size() * sizeof(Element_col);
      Element_pos * vertex = &_vertex[0];
      Element_col * colors = &_colors[0];