diff --git a/lib/Slic3r/Print/Object.pm b/lib/Slic3r/Print/Object.pm
index 55703d72..f372ecda 100644
--- a/lib/Slic3r/Print/Object.pm
+++ b/lib/Slic3r/Print/Object.pm
@@ -106,6 +106,7 @@ sub slice {
         # make layers taking custom heights into account
         my $print_z = my $slice_z = my $height = my $id = 0;
         my $first_object_layer_height = -1;
+        my $first_object_layer_distance = -1;
     
         # add raft layers
         if ($self->config->raft_layers > 0) {
@@ -123,7 +124,8 @@ sub slice {
         
             # force first layer print_z according to the contact distance
             # (the loop below will raise print_z by such height)
-            $first_object_layer_height = $distance;
+            $first_object_layer_height = $nozzle_diameter;
+            $first_object_layer_distance = $distance;
         }
     
         # loop until we have at least one layer and the max slice_z reaches the object height
@@ -147,6 +149,7 @@ sub slice {
             
             if ($first_object_layer_height != -1 && !@{$self->layers}) {
                 $height = $first_object_layer_height;
+                $print_z += ($first_object_layer_distance - $height);
             }
             
             $print_z += $height;
diff --git a/lib/Slic3r/Print/SupportMaterial.pm b/lib/Slic3r/Print/SupportMaterial.pm
index 12f63281..410a763f 100644
--- a/lib/Slic3r/Print/SupportMaterial.pm
+++ b/lib/Slic3r/Print/SupportMaterial.pm
@@ -338,7 +338,6 @@ sub support_layers_z {
     # layer_height > nozzle_diameter * 0.75
     my $nozzle_diameter = $self->print_config->get_at('nozzle_diameter', $self->object_config->support_material_extruder-1);
     my $support_material_height = max($max_object_layer_height, $nozzle_diameter * 0.75);
-    
     my @z = sort { $a <=> $b } @$contact_z, @$top_z, (map $_ + $nozzle_diameter, @$top_z);
     
     # enforce first layer height
@@ -352,7 +351,7 @@ sub support_layers_z {
         # $z[1] is last raft layer (contact layer for the first layer object)
         my $height = ($z[1] - $z[0]) / ($self->object_config->raft_layers - 1);
         splice @z, 1, 0,
-            map { int($_*100)/100 }
+            map { sprintf "%.2f", $_ }
             map { $z[0] + $height * $_ }
             0..($self->object_config->raft_layers - 1);
     }
diff --git a/t/support.t b/t/support.t
index 8939848b..4a780ddd 100644
--- a/t/support.t
+++ b/t/support.t
@@ -1,4 +1,4 @@
-use Test::More tests => 16;
+use Test::More tests => 18;
 use strict;
 use warnings;
 
@@ -130,31 +130,43 @@ use Slic3r::Test;
         'first object layer is completely supported by raft';
 }
 
-foreach my $raft_layers (2, 70) {
+{
     my $config = Slic3r::Config->new_from_defaults;
     $config->set('skirts', 0);
-    $config->set('raft_layers', $raft_layers);
     $config->set('layer_height', 0.35);
     $config->set('first_layer_height', 0.3);
     $config->set('nozzle_diameter', [0.5]);
     $config->set('support_material_extruder', 2);
     $config->set('support_material_interface_extruder', 2);
-    my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
-    my %raft_z = ();  # z => 1
-    my $tool = undef;
-    Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
-        my ($self, $cmd, $args, $info) = @_;
-        
-        if ($cmd =~ /^T(\d+)/) {
-            $tool = $1;
-        } elsif ($info->{extruding} && $info->{dist_XY} > 0) {
-            if ($tool == $config->support_material_extruder-1) {
-                $raft_z{$self->Z} = 1;
-            }
-        }
-    });
     
-    is scalar(keys %raft_z), $config->raft_layers, 'correct number of raft layers is generated';
+    my $test = sub {
+        my ($raft_layers) = @_;
+        $config->set('raft_layers', $raft_layers);
+        my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
+        my %raft_z = ();  # z => 1
+        my $tool = undef;
+        Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
+            my ($self, $cmd, $args, $info) = @_;
+        
+            if ($cmd =~ /^T(\d+)/) {
+                $tool = $1;
+            } elsif ($info->{extruding} && $info->{dist_XY} > 0) {
+                if ($tool == $config->support_material_extruder-1) {
+                    $raft_z{$self->Z} = 1;
+                }
+            }
+        });
+    
+        is scalar(keys %raft_z), $config->raft_layers, 'correct number of raft layers is generated';
+    };
+    
+    $test->(2);
+    $test->(70);
+    
+    $config->set('layer_height', 0.4);
+    $config->set('first_layer_height', 0.35);
+    $test->(3);
+    $test->(70);
 }
 
 __END__