some 'Plane Surfaces' were not plane !

benchmarks/3d/trav33D.geo

@@ -30,7 +30,7 @@ Point(8) = {r+x0+x1,0.0,y0,p0};
 Point(9) = {r+x0+x1,r+x0+x1,0.0, p0};
 Point(11) = {r+x0+x1,0.0,0.0,p0};
 Point(12) = {y,y,0.0,p0}; 
-Point(14) = {y,y,x,p0}; 
+Point(14) = {y,y,y,p0}; 
 Point(16) = {y+dx,y+dx,y+dx,p0}; 
 Point(17) = {y+dx,0.0,y+dx, p0};
 Point(18) = {0.0,r,0.0, p1};
@@ -48,7 +48,7 @@ Point(34) = {1.0,0.0,1.0,p0};
 Point(35) = {0.0,1.0+lambda,1.0,p0};
 Point(36) = {0.0,1.0+lambda,0.0,p0};
 Point(37) = {1.0+lambda,1.0+lambda,0.0,p0};
-Point(38) = {1.0+lambda,1.0+lambda,1.04,p0};
+Point(38) = {1.0+lambda,1.0+lambda,1.0,p0};
 Point(39) = {1+lambda,0.0,0.0,p0};
 Point(40) = {1+lambda,0.0,1.0,p0};
 Point(41) = {0.0,0.0,1.0,p0};