diff --git a/Intersections_2/include/CGAL/Intersections_2/Line_2_Line_2.h b/Intersections_2/include/CGAL/Intersections_2/Line_2_Line_2.h
index 8ddaaf9bf5b..d95ddec8f2a 100644
--- a/Intersections_2/include/CGAL/Intersections_2/Line_2_Line_2.h
+++ b/Intersections_2/include/CGAL/Intersections_2/Line_2_Line_2.h
@@ -36,10 +36,10 @@ namespace internal {
 template <class K>
 class Line_2_Line_2_pair {
 public:
-    enum Intersection_results {NO_INTERSECTION, POINT, LINE};
+    enum Intersection_results {NOT_COMPUTED_YET, NO_INTERSECTION, POINT, LINE};
     Line_2_Line_2_pair(typename K::Line_2 const *line1,
                        typename K::Line_2 const *line2)
-      : _line1(line1), _line2(line2), _known(false) {}
+      : _line1(line1), _line2(line2), _result(NOT_COMPUTED_YET) {}
 
     Intersection_results intersection_type() const;
 
@@ -48,7 +48,6 @@ public:
 protected:
     typename K::Line_2 const*   _line1;
     typename K::Line_2 const *  _line2;
-    mutable bool                    _known;
     mutable Intersection_results    _result;
     mutable typename K::Point_2         _intersection_point;
 };
@@ -141,11 +140,10 @@ typename Line_2_Line_2_pair<K>::Intersection_results
 Line_2_Line_2_pair<K>::intersection_type() const
 {
     typedef typename K::RT RT;
-    if (_known)
+    if (_result != NOT_COMPUTED_YET)
         return _result;
     RT nom1, nom2, denom;
     // The non const this pointer is used to cast away const.
-    _known = true;
     denom = _line1->a()*_line2->b() - _line2->a()*_line1->b();
     if (denom == RT(0)) {
         if (RT(0) == (_line1->a()*_line2->c() - _line2->a()*_line1->c()) &&
@@ -180,7 +178,7 @@ template <class K>
 typename K::Point_2
 Line_2_Line_2_pair<K>::intersection_point() const
 {
-    if (!_known)
+    if (_result == NOT_COMPUTED_YET)
         intersection_type();
     CGAL_kernel_assertion(_result == POINT);
     return _intersection_point;
@@ -190,7 +188,7 @@ template <class K>
 typename K::Line_2
 Line_2_Line_2_pair<K>::intersection_line() const
 {
-    if (!_known)
+    if (_result == NOT_COMPUTED_YET)
         intersection_type();
     CGAL_kernel_assertion(_result == LINE);
     return *_line1;
diff --git a/Intersections_2/include/CGAL/Intersections_2/Line_2_Ray_2.h b/Intersections_2/include/CGAL/Intersections_2/Line_2_Ray_2.h
index bfd102da8de..eada9a07ec2 100644
--- a/Intersections_2/include/CGAL/Intersections_2/Line_2_Ray_2.h
+++ b/Intersections_2/include/CGAL/Intersections_2/Line_2_Ray_2.h
@@ -35,10 +35,13 @@ namespace internal {
 template <class K>
 class Ray_2_Line_2_pair {
 public:
-    enum Intersection_results {NO_INTERSECTION, POINT, RAY};
+    enum Intersection_results {NOT_COMPUTED_YET, NO_INTERSECTION, POINT, RAY};
+    typedef typename K::FT FT;
     Ray_2_Line_2_pair(typename K::Ray_2 const *ray,
                       typename K::Line_2 const *line)
-      : _ray(ray), _line(line), _known(false) {}
+      : _ray(ray), _line(line), _result(NOT_COMPUTED_YET),
+        _intersection_point(K().construct_point_2_object()(ORIGIN))
+    {}
 
     Intersection_results intersection_type() const;
 
@@ -47,7 +50,6 @@ public:
 protected:
     typename K::Ray_2 const *   _ray;
     typename K::Line_2 const *  _line;
-    mutable bool                    _known;
     mutable Intersection_results    _result;
     mutable typename K::Point_2         _intersection_point;
 };
@@ -94,7 +96,7 @@ intersection(const typename K::Line_2 &line,
              const typename K::Ray_2 &ray,
              const K& k)
 {
-  return internal::intersection(ray, line, k);
+    return internal::intersection(ray, line, k);
 }
 
 
@@ -115,14 +117,14 @@ template <class K>
 typename Ray_2_Line_2_pair<K>::Intersection_results
 Ray_2_Line_2_pair<K>::intersection_type() const
 {
-    if (_known)
+    if (_result != NOT_COMPUTED_YET)
         return _result;
     // The non const this pointer is used to cast away const.
-    _known = true;
     const typename K::Line_2 &l1 = _ray->supporting_line();
     Line_2_Line_2_pair<K> linepair(&l1, _line);
     switch ( linepair.intersection_type()) {
     case Line_2_Line_2_pair<K>::NO_INTERSECTION:
+    default:
         _result = NO_INTERSECTION;
         break;
     case Line_2_Line_2_pair<K>::POINT:
@@ -142,7 +144,7 @@ template <class K>
 typename K::Point_2
 Ray_2_Line_2_pair<K>::intersection_point() const
 {
-    if (!_known)
+    if (_result == NOT_COMPUTED_YET)
         intersection_type();
     CGAL_kernel_assertion(_result == POINT);
     return _intersection_point;
@@ -152,7 +154,7 @@ template <class K>
 typename K::Ray_2
 Ray_2_Line_2_pair<K>::intersection_ray() const
 {
-    if (!_known)
+    if (_result == NOT_COMPUTED_YET)
         intersection_type();
     CGAL_kernel_assertion(_result == RAY);
     return *_ray;
diff --git a/Intersections_2/include/CGAL/Intersections_2/Segment_2_Segment_2.h b/Intersections_2/include/CGAL/Intersections_2/Segment_2_Segment_2.h
index 663361e4eb9..ba3d8b9567c 100644
--- a/Intersections_2/include/CGAL/Intersections_2/Segment_2_Segment_2.h
+++ b/Intersections_2/include/CGAL/Intersections_2/Segment_2_Segment_2.h
@@ -308,6 +308,7 @@ Segment_2_Segment_2_pair<K>::intersection_type() const
     Line_2_Line_2_pair<K> linepair(&l1, &l2);
     switch ( linepair.intersection_type()) {
     case Line_2_Line_2_pair<K>::NO_INTERSECTION:
+    default:
         _result = NO_INTERSECTION;
         break;
     case Line_2_Line_2_pair<K>::POINT:
diff --git a/Intersections_2/include/CGAL/Intersections_2/internal/Straight_2.h b/Intersections_2/include/CGAL/Intersections_2/internal/Straight_2.h
index 47424bb3122..fa63e699475 100644
--- a/Intersections_2/include/CGAL/Intersections_2/internal/Straight_2.h
+++ b/Intersections_2/include/CGAL/Intersections_2/internal/Straight_2.h
@@ -275,6 +275,7 @@ cut_right_off(typename K::Line_2 const & cutter)
     Line_2_Line_2_pair<K> pair(&support_, &cutter);
     switch (pair.intersection_type()) {
     case Line_2_Line_2_pair<K>::NO_INTERSECTION:
+    default:
         if (cutter.has_on_negative_side(support_.point()))
             bound_state_ = LINE_EMPTY;
         break;
diff --git a/Kernel_23/examples/Kernel_23/MyPointC2.h b/Kernel_23/examples/Kernel_23/MyPointC2.h
index de1c7ee6cd6..e4b2f3ff0ce 100644
--- a/Kernel_23/examples/Kernel_23/MyPointC2.h
+++ b/Kernel_23/examples/Kernel_23/MyPointC2.h
@@ -21,7 +21,6 @@ public:
     *(vec+1) = 0;
   }
 
-
   MyPointC2(const double x, const double y, int c = 0)
     : col(c)
   {
diff --git a/Nef_2/include/CGAL/Nef_2/debug.h b/Nef_2/include/CGAL/Nef_2/debug.h
index ff850cdf052..ce77dc610c6 100644
--- a/Nef_2/include/CGAL/Nef_2/debug.h
+++ b/Nef_2/include/CGAL/Nef_2/debug.h
@@ -59,8 +59,7 @@
 
 #ifndef NDEBUG
 #define CGAL_NEF_TRACEN(t) if((debugthread%CGAL_NEF_DEBUG)==0) \
- std::cerr<< " "<<t<<std::endl; \
- std::cerr.flush()
+ std::cerr<< " "<<t<<std::endl;
 #else
 #define CGAL_NEF_TRACEN(t)
 #endif
diff --git a/Number_types/include/CGAL/FPU.h b/Number_types/include/CGAL/FPU.h
index 1d290381603..6d5f02a3075 100644
--- a/Number_types/include/CGAL/FPU.h
+++ b/Number_types/include/CGAL/FPU.h
@@ -75,8 +75,8 @@ extern "C" {
 // Pure and safe SSE2 mode (g++ -mfpmath=sse && (-msse2 || -march=pentium4))
 // can be detected by :
 // TODO : see what Intel and VC++ have to say about this.
-#if defined __FLT_EVAL_METHOD__ && defined __SSE2_MATH__ && \
-      (__FLT_EVAL_METHOD__ == 0 || __FLT_EVAL_METHOD__ == 1)
+#if defined _M_X64 || ( defined __FLT_EVAL_METHOD__ && defined __SSE2_MATH__ && \
+                        (__FLT_EVAL_METHOD__ == 0 || __FLT_EVAL_METHOD__ == 1) )
 #  define CGAL_SAFE_SSE2
 #  include <xmmintrin.h>
 #endif
@@ -90,7 +90,7 @@ extern "C" {
 #if !defined CGAL_IA_NO_X86_OVER_UNDER_FLOW_PROTECT && \
   (((defined __i386__ || defined __x86_64__) && !defined CGAL_SAFE_SSE2) \
    || defined __ia64__ \
-   || defined _M_IX86 || defined _M_X64 || defined _M_IA64 \
+   || defined _M_IX86 || defined _M_IA64 \
    || (defined FLT_EVAL_METHOD && FLT_EVAL_METHOD != 0 && FLT_EVAL_METHOD != 1))
 #  define CGAL_FPU_HAS_EXCESS_PRECISION
 #endif
diff --git a/Triangulation_2/include/CGAL/Triangulation_2.h b/Triangulation_2/include/CGAL/Triangulation_2.h
index 3f73f238eae..88e246f0f85 100644
--- a/Triangulation_2/include/CGAL/Triangulation_2.h
+++ b/Triangulation_2/include/CGAL/Triangulation_2.h
@@ -2976,9 +2976,9 @@ exact_locate(const Point& p,
              Face_handle start) const
 #endif // no CGAL_NO_STRUCTURAL_FILTERING
 {
+  li = 4; //general init to avoid warnings.
+  lt = OUTSIDE_AFFINE_HULL; //same
   if (dimension() < 0) {
-    lt = OUTSIDE_AFFINE_HULL;
-    li = 4; // li should not be used in this case
     return Face_handle();
   }
   if( dimension() == 0) {
@@ -2987,10 +2987,6 @@ exact_locate(const Point& p,
     if (xy_equal(p,finite_vertex()->face()->vertex(0)->point())){
       lt = VERTEX ;
     }
-    else{
-      lt = OUTSIDE_AFFINE_HULL;
-    }
-    li = 4; // li should not be used in this case
     return Face_handle();
   }
   if(dimension() == 1){