diff --git a/vcg/container/simple_temporary_data.h b/vcg/container/simple_temporary_data.h
index 27669474..284dfcfe 100644
--- a/vcg/container/simple_temporary_data.h
+++ b/vcg/container/simple_temporary_data.h
@@ -93,7 +93,7 @@ public:
 
 	void clear(){ datasize = 0;}
 
-	const unsigned int &  size() const { return datasize;}
+	const unsigned int  size() const { return datasize;}
 
 	bool  & operator [](const int & i){return data[i];}
 
diff --git a/wrap/gui/trackball.cpp b/wrap/gui/trackball.cpp
index 5123e27a..fff43e69 100644
--- a/wrap/gui/trackball.cpp
+++ b/wrap/gui/trackball.cpp
@@ -125,8 +125,8 @@ Transform::Transform() {
 }
 
 Trackball::Trackball(): current_button(0), current_mode(NULL), inactive_mode(NULL),
-			dragging(false), spinnable(true), spinning(false),
-			history_size(10), last_time(0), fixedTimestepMode(false) {
+			dragging(false), last_time(0), spinnable(true), spinning(false),
+			history_size(10), fixedTimestepMode(false) {
   setDefaultMapping ();
 }
 
diff --git a/wrap/gui/trackball.h b/wrap/gui/trackball.h
index 988ecf85..555b7a2b 100644
--- a/wrap/gui/trackball.h
+++ b/wrap/gui/trackball.h
@@ -201,8 +201,8 @@ public:
   ~Trackball();
 	
 	private:
-	// TriMesh cannot be copied. Use Append (see vcg/complex/trimesh/append.h)
-	Trackball operator =(const Trackball &  m){}
+	// Trackball must not be copied. Use Append (see vcg/complex/trimesh/append.h)
+	Trackball operator =(const Trackball &  /*m*/){ assert(0); return *this; }
 	public:
   /*!
     @brief Reset the trackball.
diff --git a/wrap/gui/trackmode.cpp b/wrap/gui/trackmode.cpp
index 96297209..d73031ec 100644
--- a/wrap/gui/trackmode.cpp
+++ b/wrap/gui/trackmode.cpp
@@ -885,7 +885,7 @@ void NavigatorWasdMode::Animate(unsigned int msec, Trackball * tb){
     vel = current_speed.Norm();
 		step_x += vel*sec;
 	  float step_current_min = (float)fabs(sin( step_x*M_PI / step_length ))*step_height;
-		if (step_current<step_current_min); step_current=step_current_min;
+		if (step_current<step_current_min) step_current=step_current_min;
 	}
 
 	current_speed*=pow(dumping,sec);