diff --git a/samples/opengl/isosurf/isosurf.cpp b/samples/opengl/isosurf/isosurf.cpp
index fb8039efa7..8798d37922 100644
--- a/samples/opengl/isosurf/isosurf.cpp
+++ b/samples/opengl/isosurf/isosurf.cpp
@@ -51,7 +51,6 @@ GLboolean g_lighting = GL_TRUE;
 
 IMPLEMENT_APP(MyApp)
 
-// `Main program' equivalent, creating windows and returning main app frame
 bool MyApp::OnInit()
 {
     if ( !wxApp::OnInit() )
@@ -93,9 +92,8 @@ BEGIN_EVENT_TABLE(MyFrame, wxFrame)
     EVT_MENU(wxID_EXIT, MyFrame::OnExit)
 END_EVENT_TABLE()
 
-// My frame constructor
 MyFrame::MyFrame(wxFrame *frame, const wxString& title, const wxPoint& pos,
-    const wxSize& size, long style)
+                 const wxSize& size, long style)
     : wxFrame(frame, wxID_ANY, title, pos, size, style),
       m_canvas(NULL)
 {
@@ -234,6 +232,10 @@ void TestGLCanvas::LoadSurface(const wxString& filename)
 
     wxLogMessage(_T("Loaded %d vertices, %d triangles from '%s'"),
                  m_numverts, m_numverts-2, filename.c_str());
+                 
+    // NOTE: for some reason under wxGTK the following is required to avoid that
+    //       the surface gets rendered in a small rectangle in the top-left corner of the frame
+    PostSizeEventToParent();
 }
 
 void TestGLCanvas::OnPaint( wxPaintEvent& WXUNUSED(event) )
@@ -345,9 +347,9 @@ void TestGLCanvas::OnMouseEvent(wxMouseEvent& event)
     // (for key events).
     event.Skip();
 
-    if(event.LeftIsDown())
+    if (event.LeftIsDown())
     {
-        if(!dragging)
+        if (!dragging)
         {
             dragging = 1;
         }