diff --git a/include/wx/gtk/gauge.h b/include/wx/gtk/gauge.h
index 11ec3318c1..c1d22c1a98 100644
--- a/include/wx/gtk/gauge.h
+++ b/include/wx/gtk/gauge.h
@@ -42,25 +42,32 @@ extern const wxChar* wxGaugeNameStr;
 class wxGauge: public wxControl
 {
 public:
-    inline wxGauge() { m_rangeMax = 0; m_gaugePos = 0; m_useProgressBar = TRUE; }
+    wxGauge() { Init(); }
 
-    inline wxGauge( wxWindow *parent, wxWindowID id, int range,
-           const wxPoint& pos = wxDefaultPosition,
-           const wxSize& size = wxDefaultSize,
-           long style = wxGA_HORIZONTAL,
-           const wxValidator& validator = wxDefaultValidator,
-           const wxString& name = wxGaugeNameStr )
+    wxGauge( wxWindow *parent,
+             wxWindowID id,
+             int range,
+             const wxPoint& pos = wxDefaultPosition,
+             const wxSize& size = wxDefaultSize,
+             long style = wxGA_HORIZONTAL,
+             const wxValidator& validator = wxDefaultValidator,
+             const wxString& name = wxGaugeNameStr )
     {
-      Create(parent, id, range, pos, size, style, validator, name);
+        Init();
+
+        Create(parent, id, range, pos, size, style, validator, name);
     }
-    bool Create( wxWindow *parent, wxWindowID id, int range,
-           const wxPoint& pos = wxDefaultPosition,
-           const wxSize& size = wxDefaultSize,
-           long style = wxGA_HORIZONTAL,
-           const wxValidator& validator = wxDefaultValidator,
-           const wxString& name = wxGaugeNameStr );
-    void SetShadowWidth( int WXUNUSED(w) ) {};
-    void SetBezelFace( int WXUNUSED(w) ) {};
+
+    bool Create( wxWindow *parent,
+                 wxWindowID id, int range,
+                 const wxPoint& pos = wxDefaultPosition,
+                 const wxSize& size = wxDefaultSize,
+                 long style = wxGA_HORIZONTAL,
+                 const wxValidator& validator = wxDefaultValidator,
+                 const wxString& name = wxGaugeNameStr );
+
+    void SetShadowWidth( int WXUNUSED(w) ) { }
+    void SetBezelFace( int WXUNUSED(w) ) { }
     void SetRange( int r );
     void SetValue( int pos );
     int GetShadowWidth() const { return 0; };
@@ -68,17 +75,27 @@ public:
     int GetRange() const;
     int GetValue() const;
 
-    // Are we a Win95/GTK progress bar, or a normal gauge?
-    inline bool GetProgressBar() const { return m_useProgressBar; }
-    
     // implementation
     // -------------
-    
+
     void ApplyWidgetStyle();
-    int      m_rangeMax;
-    int      m_gaugePos;
-    bool     m_useProgressBar;
-   
+
+    // the max and current gauge values
+    int m_rangeMax,
+        m_gaugePos;
+
+    // obsolete functions, don't use
+#ifdef WXWIN_COMPATIBILITY_2_2
+    bool GetProgressBar() const { return TRUE; }
+#endif // WXWIN_COMPATIBILITY_2_2
+
+protected:
+    // common part of all ctors
+    void Init() { m_rangeMax = m_gaugePos = 0; }
+
+    // set the gauge value to the value of m_gaugePos
+    void DoSetGauge();
+
 private:
     DECLARE_DYNAMIC_CLASS(wxGauge)
 };
diff --git a/include/wx/gtk1/gauge.h b/include/wx/gtk1/gauge.h
index 11ec3318c1..c1d22c1a98 100644
--- a/include/wx/gtk1/gauge.h
+++ b/include/wx/gtk1/gauge.h
@@ -42,25 +42,32 @@ extern const wxChar* wxGaugeNameStr;
 class wxGauge: public wxControl
 {
 public:
-    inline wxGauge() { m_rangeMax = 0; m_gaugePos = 0; m_useProgressBar = TRUE; }
+    wxGauge() { Init(); }
 
-    inline wxGauge( wxWindow *parent, wxWindowID id, int range,
-           const wxPoint& pos = wxDefaultPosition,
-           const wxSize& size = wxDefaultSize,
-           long style = wxGA_HORIZONTAL,
-           const wxValidator& validator = wxDefaultValidator,
-           const wxString& name = wxGaugeNameStr )
+    wxGauge( wxWindow *parent,
+             wxWindowID id,
+             int range,
+             const wxPoint& pos = wxDefaultPosition,
+             const wxSize& size = wxDefaultSize,
+             long style = wxGA_HORIZONTAL,
+             const wxValidator& validator = wxDefaultValidator,
+             const wxString& name = wxGaugeNameStr )
     {
-      Create(parent, id, range, pos, size, style, validator, name);
+        Init();
+
+        Create(parent, id, range, pos, size, style, validator, name);
     }
-    bool Create( wxWindow *parent, wxWindowID id, int range,
-           const wxPoint& pos = wxDefaultPosition,
-           const wxSize& size = wxDefaultSize,
-           long style = wxGA_HORIZONTAL,
-           const wxValidator& validator = wxDefaultValidator,
-           const wxString& name = wxGaugeNameStr );
-    void SetShadowWidth( int WXUNUSED(w) ) {};
-    void SetBezelFace( int WXUNUSED(w) ) {};
+
+    bool Create( wxWindow *parent,
+                 wxWindowID id, int range,
+                 const wxPoint& pos = wxDefaultPosition,
+                 const wxSize& size = wxDefaultSize,
+                 long style = wxGA_HORIZONTAL,
+                 const wxValidator& validator = wxDefaultValidator,
+                 const wxString& name = wxGaugeNameStr );
+
+    void SetShadowWidth( int WXUNUSED(w) ) { }
+    void SetBezelFace( int WXUNUSED(w) ) { }
     void SetRange( int r );
     void SetValue( int pos );
     int GetShadowWidth() const { return 0; };
@@ -68,17 +75,27 @@ public:
     int GetRange() const;
     int GetValue() const;
 
-    // Are we a Win95/GTK progress bar, or a normal gauge?
-    inline bool GetProgressBar() const { return m_useProgressBar; }
-    
     // implementation
     // -------------
-    
+
     void ApplyWidgetStyle();
-    int      m_rangeMax;
-    int      m_gaugePos;
-    bool     m_useProgressBar;
-   
+
+    // the max and current gauge values
+    int m_rangeMax,
+        m_gaugePos;
+
+    // obsolete functions, don't use
+#ifdef WXWIN_COMPATIBILITY_2_2
+    bool GetProgressBar() const { return TRUE; }
+#endif // WXWIN_COMPATIBILITY_2_2
+
+protected:
+    // common part of all ctors
+    void Init() { m_rangeMax = m_gaugePos = 0; }
+
+    // set the gauge value to the value of m_gaugePos
+    void DoSetGauge();
+
 private:
     DECLARE_DYNAMIC_CLASS(wxGauge)
 };
diff --git a/src/gtk/gauge.cpp b/src/gtk/gauge.cpp
index 917ab60307..f180206c79 100644
--- a/src/gtk/gauge.cpp
+++ b/src/gtk/gauge.cpp
@@ -15,18 +15,22 @@
 
 #if wxUSE_GAUGE
 
-#include <gdk/gdk.h>
 #include <gtk/gtk.h>
 
 //-----------------------------------------------------------------------------
 // wxGauge
 //-----------------------------------------------------------------------------
 
-IMPLEMENT_DYNAMIC_CLASS(wxGauge,wxControl)
+IMPLEMENT_DYNAMIC_CLASS(wxGauge, wxControl)
 
-bool wxGauge::Create( wxWindow *parent, wxWindowID id,  int range,
-    const wxPoint& pos, const wxSize& size,
-    long style, const wxValidator& validator, const wxString& name )
+bool wxGauge::Create( wxWindow *parent,
+                      wxWindowID id,
+                      int range,
+                      const wxPoint& pos,
+                      const wxSize& size,
+                      long style,
+                      const wxValidator& validator,
+                      const wxString& name )
 {
     m_needParent = TRUE;
 
@@ -38,12 +42,13 @@ bool wxGauge::Create( wxWindow *parent, wxWindowID id,  int range,
     }
 
     m_rangeMax = range;
-    m_gaugePos = 0;
-    m_useProgressBar = TRUE;
 
     m_widget = gtk_progress_bar_new();
-    if( style & wxGA_VERTICAL)
-        gtk_progress_bar_set_orientation( GTK_PROGRESS_BAR(m_widget) , GTK_PROGRESS_BOTTOM_TO_TOP );
+    if ( style & wxGA_VERTICAL )
+    {
+        gtk_progress_bar_set_orientation( GTK_PROGRESS_BAR(m_widget),
+                                          GTK_PROGRESS_BOTTOM_TO_TOP );
+    }
 
     m_parent->DoAddChild( this );
 
@@ -54,20 +59,31 @@ bool wxGauge::Create( wxWindow *parent, wxWindowID id,  int range,
     return TRUE;
 }
 
-void wxGauge::SetRange( int r )
+void wxGauge::DoSetGauge()
 {
-    m_rangeMax = r;
-    if (m_gaugePos > m_rangeMax) m_gaugePos = m_rangeMax;
+    wxASSERT_MSG( 0 <= m_gaugePos && m_gaugePos <= m_rangeMax,
+                  _T("invalid gauge position in DoSetGauge()") );
 
-    gtk_progress_bar_update( GTK_PROGRESS_BAR(m_widget), ((float)m_gaugePos)/m_rangeMax );
+    gtk_progress_bar_update( GTK_PROGRESS_BAR(m_widget),
+                             m_rangeMax ? ((float)m_gaugePos)/m_rangeMax : 0.);
+}
+
+void wxGauge::SetRange( int range )
+{
+    m_rangeMax = range;
+    if (m_gaugePos > m_rangeMax)
+        m_gaugePos = m_rangeMax;
+
+    DoSetGauge();
 }
 
 void wxGauge::SetValue( int pos )
 {
-    m_gaugePos = pos;
-    if (m_gaugePos > m_rangeMax) m_gaugePos = m_rangeMax;
+    wxCHECK_RET( pos <= m_rangeMax, _T("invalid value in wxGauge::SetValue()") );
 
-    gtk_progress_bar_update( GTK_PROGRESS_BAR(m_widget), ((float)m_gaugePos)/m_rangeMax );
+    m_gaugePos = pos;
+
+    DoSetGauge();
 }
 
 int wxGauge::GetRange() const
diff --git a/src/gtk1/gauge.cpp b/src/gtk1/gauge.cpp
index 917ab60307..f180206c79 100644
--- a/src/gtk1/gauge.cpp
+++ b/src/gtk1/gauge.cpp
@@ -15,18 +15,22 @@
 
 #if wxUSE_GAUGE
 
-#include <gdk/gdk.h>
 #include <gtk/gtk.h>
 
 //-----------------------------------------------------------------------------
 // wxGauge
 //-----------------------------------------------------------------------------
 
-IMPLEMENT_DYNAMIC_CLASS(wxGauge,wxControl)
+IMPLEMENT_DYNAMIC_CLASS(wxGauge, wxControl)
 
-bool wxGauge::Create( wxWindow *parent, wxWindowID id,  int range,
-    const wxPoint& pos, const wxSize& size,
-    long style, const wxValidator& validator, const wxString& name )
+bool wxGauge::Create( wxWindow *parent,
+                      wxWindowID id,
+                      int range,
+                      const wxPoint& pos,
+                      const wxSize& size,
+                      long style,
+                      const wxValidator& validator,
+                      const wxString& name )
 {
     m_needParent = TRUE;
 
@@ -38,12 +42,13 @@ bool wxGauge::Create( wxWindow *parent, wxWindowID id,  int range,
     }
 
     m_rangeMax = range;
-    m_gaugePos = 0;
-    m_useProgressBar = TRUE;
 
     m_widget = gtk_progress_bar_new();
-    if( style & wxGA_VERTICAL)
-        gtk_progress_bar_set_orientation( GTK_PROGRESS_BAR(m_widget) , GTK_PROGRESS_BOTTOM_TO_TOP );
+    if ( style & wxGA_VERTICAL )
+    {
+        gtk_progress_bar_set_orientation( GTK_PROGRESS_BAR(m_widget),
+                                          GTK_PROGRESS_BOTTOM_TO_TOP );
+    }
 
     m_parent->DoAddChild( this );
 
@@ -54,20 +59,31 @@ bool wxGauge::Create( wxWindow *parent, wxWindowID id,  int range,
     return TRUE;
 }
 
-void wxGauge::SetRange( int r )
+void wxGauge::DoSetGauge()
 {
-    m_rangeMax = r;
-    if (m_gaugePos > m_rangeMax) m_gaugePos = m_rangeMax;
+    wxASSERT_MSG( 0 <= m_gaugePos && m_gaugePos <= m_rangeMax,
+                  _T("invalid gauge position in DoSetGauge()") );
 
-    gtk_progress_bar_update( GTK_PROGRESS_BAR(m_widget), ((float)m_gaugePos)/m_rangeMax );
+    gtk_progress_bar_update( GTK_PROGRESS_BAR(m_widget),
+                             m_rangeMax ? ((float)m_gaugePos)/m_rangeMax : 0.);
+}
+
+void wxGauge::SetRange( int range )
+{
+    m_rangeMax = range;
+    if (m_gaugePos > m_rangeMax)
+        m_gaugePos = m_rangeMax;
+
+    DoSetGauge();
 }
 
 void wxGauge::SetValue( int pos )
 {
-    m_gaugePos = pos;
-    if (m_gaugePos > m_rangeMax) m_gaugePos = m_rangeMax;
+    wxCHECK_RET( pos <= m_rangeMax, _T("invalid value in wxGauge::SetValue()") );
 
-    gtk_progress_bar_update( GTK_PROGRESS_BAR(m_widget), ((float)m_gaugePos)/m_rangeMax );
+    m_gaugePos = pos;
+
+    DoSetGauge();
 }
 
 int wxGauge::GetRange() const