diff --git a/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/gfx/Curve_renderer_2.h b/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/gfx/Curve_renderer_2.h
index 25534e963af..d6aa37ca4c0 100644
--- a/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/gfx/Curve_renderer_2.h
+++ b/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/gfx/Curve_renderer_2.h
@@ -1023,7 +1023,7 @@ void draw_lump(std::vector< Coord_2 >& rev_points, int& last_x,
             pix.level = 0;
             pix.sub_x = 0;
             pix.sub_y = 0;
-            Gfx_OUT(witness << " " << prev_pix << std::endl);
+            //Gfx_OUT(witness << " " << prev_pix << std::endl);
         } else {
             ux = pix.x;
             uy = pix.y;
@@ -1307,8 +1307,7 @@ bool get_seed_point(const Rational& seed, Pixel_2& start, int *dir,
         s_stack.push(Seed_point(start, dir[1], b_taken[1], b_coincide));
     }
     if(b_coincide)
-        Gfx_DETAILED_OUT("seed point with coincide branches found" <<
-            std::endl);
+        Gfx_OUT("seed point with coincide branches found" << std::endl);
     return true;
 }
 
@@ -1326,6 +1325,11 @@ bool test_pixel(const Pixel_2& pix, int *dir, int *b_taken, bool& b_coincide)
     // bottom(2), top(3), left(0), right(1)
     int n_sign = 0, i, j, n_dir = 0, shift, n_local, new_dir;
     get_polynomials(CGAL_Y_RANGE, box[0]);
+
+
+    Gfx_OUT("test pixel: " << pix << "--------------------------------\n");
+    dump_neighbourhood(pix);
+    Gfx_OUT("----------------------------------------------\n\n");
     
     b_coincide = false;
     int n_corner_dir = 0, corner_dir[] = {-1, -1};
@@ -2165,7 +2169,7 @@ Lexit:
 inline bool get_range_1(int var, const NT& lower, const NT& upper, 
     const NT& key, const Poly_1& poly, int check = 1)
 {
-    bool res = engine.get_range_AARD_1(var, lower, upper, key, poly, check);
+    bool res = engine.get_range_QF_1(var, lower, upper, key, poly, check);
         //engine.get_range_MAA_1(var, lower, upper, key, poly, check);
     return res;
 }
@@ -2469,7 +2473,7 @@ inline bool is_isolated_pixel(const Pixel_2& pix) {
 
 // DEBUG ONLY
 void dump_neighbourhood(const Pixel_2& pix) {
-#ifdef Gfx_USE_DETAILED_OUT
+#ifdef Gfx_USE_OUT
     CGAL::set_mode(std::cerr, CGAL::IO::PRETTY);
     CGAL::set_mode(std::cout, CGAL::IO::PRETTY);
 
@@ -2646,7 +2650,7 @@ void dump_neighbourhood(const Pixel_2& pix) {
     Gfx_OUT("val = " << b << std::endl);
     if(a*b < 0) 
         Gfx_OUT("sign change at segment 2" << std::endl);
-#endif
+#endif // Gfx_USE_OUT
 }
 
 //!@} 
diff --git a/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/gfx/Curve_renderer_internals.h b/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/gfx/Curve_renderer_internals.h
index ef4bffb0a8b..d00428e9315 100644
--- a/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/gfx/Curve_renderer_internals.h
+++ b/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/gfx/Curve_renderer_internals.h
@@ -625,6 +625,7 @@ bool get_range_AARD_1(int var,
     }
     zero_bounds = ((eval1&eval2) == 0);
     if(eval1*eval2 < 0) {
+        //std::cerr << "eval1 = " << low << "; eval2 = " << up << std::endl;
         return true;
     } 
     return false;
@@ -759,6 +760,8 @@ bool get_range_QF_1(int var, const NT& l_, const NT& r_, const NT& key,
         eval1 = CGAL_SGN(low);
         eval2 = CGAL_SGN(up);
     }
+    //if(eval1*eval2 < 0)
+      //  std::cerr << "eval1 = " << low << "; eval2 = " << up << std::endl;
     zero_bounds = ((eval1 & eval2) == 0);
     return (eval1*eval2 < 0);
 }
@@ -831,7 +834,7 @@ bool get_range_MAA_1(int var, const NT& l_, const NT& r_, const NT& key,
     typename Renderer_traits::Extract_eval extract;
     unsigned index = CGAL_RECURSIVE_DER_MAX_DEGREE;
     if(index >= der->size()) {
-        low = up = extract(poly.lcoeff()) * (*der_it_2).lcoeff();
+        low = up = extract(poly.lcoeff()) * (der->end()-1)->lcoeff();
     } else {
         der_it_2 = der->begin()+index;
         low = 1;
diff --git a/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/gfx/Curve_renderer_traits.h b/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/gfx/Curve_renderer_traits.h
index 831176d2cb8..fa2e515637b 100644
--- a/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/gfx/Curve_renderer_traits.h
+++ b/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/gfx/Curve_renderer_traits.h
@@ -325,7 +325,7 @@ struct Curve_renderer_traits<CGAL::Interval_nt<true>, CORE::BigRat > :
         { return (CGAL_ABS(x) <= 1e-16); }
     };
 
-    static const unsigned MAX_SUBDIVISION_LEVEL = 6;
+    static const unsigned MAX_SUBDIVISION_LEVEL = 12;
 };
 
 //! Specialization for \c CORE::BigFloat
@@ -374,7 +374,7 @@ struct Curve_renderer_traits<CORE::BigFloat, class CORE::BigRat>
         { x.makeExact(); }
     };
 
-    static const unsigned MAX_SUBDIVISION_LEVEL = 6;
+    static const unsigned MAX_SUBDIVISION_LEVEL = 12;
 };
 
 //! Specialization for \c CORE::BigRat