diff --git a/Nef_2/demo/Nef_2/CMakeLists.txt b/Nef_2/demo/Nef_2/CMakeLists.txt
index 327c7282afa..7226237a65a 100644
--- a/Nef_2/demo/Nef_2/CMakeLists.txt
+++ b/Nef_2/demo/Nef_2/CMakeLists.txt
@@ -20,6 +20,7 @@ find_package(Qt3-patched)
 
 if ( CGAL_FOUND AND CGAL_Qt3_FOUND AND QT3_FOUND )
 
+  include_directories(BEFORE ../../include)
   # use the Qt MOC preprocessor on classes that derives from QObject
   include( Qt3Macros-patched )
   qt3_generate_moc( "${CMAKE_CURRENT_SOURCE_DIR}/nef_2.cpp" nef_2.moc )
diff --git a/Nef_2/include/CGAL/Nef_2/Polynomial.h b/Nef_2/include/CGAL/Nef_2/Polynomial.h
index c9854a8640a..4195888f9d7 100644
--- a/Nef_2/include/CGAL/Nef_2/Polynomial.h
+++ b/Nef_2/include/CGAL/Nef_2/Polynomial.h
@@ -352,6 +352,7 @@ template <class pNT> class Polynomial :
   /*{\Mop returns the sign of the limit process for $x \rightarrow \infty$
   (the sign of the leading coefficient).}*/
   { const NT& leading_coeff = this->ptr()->coeff.back();
+    if (degree() < 0) return CGAL::ZERO;
     if (leading_coeff < NT(0)) return (CGAL::NEGATIVE);
     if (leading_coeff > NT(0)) return (CGAL::POSITIVE);
     return CGAL::ZERO;
@@ -1232,6 +1233,7 @@ Polynomial<NT> operator * (const Polynomial<NT>& p1,
                             const Polynomial<NT>& p2)
 {
   typedef typename Polynomial<NT>::size_type size_type;
+  if (p1.degree()<0 || p2.degree()<0) return p1;
   CGAL_assertion(p1.degree()>=0 && p2.degree()>=0);
   Polynomial<NT>  p( size_type(p1.degree()+p2.degree()+1) ); 
   // initialized with zeros
diff --git a/Nef_2/include/CGAL/Nef_2/geninfo.h b/Nef_2/include/CGAL/Nef_2/geninfo.h
index af720eec1c0..232def6eb3f 100644
--- a/Nef_2/include/CGAL/Nef_2/geninfo.h
+++ b/Nef_2/include/CGAL/Nef_2/geninfo.h
@@ -41,6 +41,7 @@ misuse memory problems occur.}*/
 
 /*{\Moperations 2 1}*/
 
+  #ifdef CGAL_USE_FORMER_GENINFO
   static void create(GenPtr& p) 
   /*{\Mstatic create a slot for an object of type |T| referenced 
     via |p|.}*/
@@ -71,6 +72,16 @@ misuse memory problems occur.}*/
     if (sizeof(T) >  sizeof(GenPtr)) delete (T*) p;
     p=0;
   }
+  #else //CGAL_USE_FORMER_GENINFO
+  static void create(GenPtr& p)  { p = (GenPtr) new T; }
+  static T& access(GenPtr& p)  { return *(T*)p;  }
+  static const T& const_access(const GenPtr& p) 
+  { return *(const T*)p;   }
+  static void clear(GenPtr& p){ 
+    delete (T*) p;
+    p=0;
+  }
+  #endif  //CGAL_USE_FORMER_GENINFO
 
 };