diff --git a/magicmaze/filemap.rb b/magicmaze/filemap.rb
index 69bf28b..cd5ba4c 100644
--- a/magicmaze/filemap.rb
+++ b/magicmaze/filemap.rb
@@ -55,14 +55,23 @@ def initialize( filename, monster_maker = nil )
       }
     end
 
+
+    def convert_string_to_bytes( str )
+      if str.respond_to?(:bytes) then
+	str.bytes.collect{|i| i } # Ruby 1.9
+      else
+	str # Ruby 1.8
+      end
+    end
     ##
     # Extract various data from the header part of the map.
-    def extract_from_header( header_data )
+    def extract_from_header( header_data_str )
+      header_data = convert_string_to_bytes( header_data_str )
       @checksum = header_data[16] + (header_data[17]<<8)
       @startx =   header_data[24]
       @starty =   header_data[25]
       @default_wall_tile = header_data[30]
-      @last_level = header_data[32]&BLOCKED_BIT==BLOCKED_BIT
+      @last_level = header_data[32] & BLOCKED_BIT == BLOCKED_BIT
 
       @title = ""
       index = 128        
@@ -123,7 +132,7 @@ def each_column( &block )
     # If the most significant bit is set, it is blocked.
     # If the coordinate is outside the map, a default block is returned.
     def get_background_data( x, y )
-      row = @map_rows[y]
+      row = convert_string_to_bytes(@map_rows[y])
       row ||= EMPTY_ROW
       index = x*2
       if (index<0||index>=row.size) then
@@ -143,7 +152,8 @@ def get_background_tile( x, y )
     ##
     # return object code for the position given.
     def get_object( x, y )
-      object = @map_rows[y][x*2+1]
+      row = convert_string_to_bytes(@map_rows[y])
+      object = row[x*2+1]
     end
     alias :get_object_data :get_object
 
diff --git a/magicmaze/graphics.rb b/magicmaze/graphics.rb
index 0b63d4c..cad7cab 100644
--- a/magicmaze/graphics.rb
+++ b/magicmaze/graphics.rb
@@ -490,7 +490,7 @@ def show_help
 	'Alt :-  Cast secondary spell',
 	'X / Z :- Toggle attack spell',
 	'A / S :- Toggle secondary spell',
-	'',
+	'', # Failed for RubySDL2.0.1 and Ruby1.9.1-p1
 	'Esc / Q :- Quit playing',
 	'F9 / R :- Restart level',
 	# '[F4]: Load game    [F5]: Save game',
@@ -502,7 +502,7 @@ def show_help
       y_offset = 0
       font = @font16
       lines.each{|line|
-	write_smooth_text( line, 5, y_offset, font )
+	write_smooth_text( line, 5, y_offset, font ) if line.size.nonzero? # Failed for RubySDL2.0.1 and Ruby1.9.1-p1 on empty string.
 	y_offset+= font.height
       }
       
diff --git a/magicmaze/images.rb b/magicmaze/images.rb
index fd3d149..4489cc1 100644
--- a/magicmaze/images.rb
+++ b/magicmaze/images.rb
@@ -87,7 +87,7 @@ def write_text( text, x, y, font = @font16 )
     end
 
     def write_smooth_text( text, x, y, font = @font16,r=255,g=255,b=255 )
-      font.drawBlendedUTF8(@screen, text, x,y, r,g,b)
+      font.drawBlendedUTF8(@screen, text, x,y, r,g,b) # Failed for RubySDL2.0.1 and Ruby1.9.1-p1 on multiline strings.
     end
 
     def set_palette( pal, start_color = 0 )
diff --git a/magicmaze/map.rb b/magicmaze/map.rb
index 122ef0e..112a864 100644
--- a/magicmaze/map.rb
+++ b/magicmaze/map.rb
@@ -10,6 +10,7 @@
 ############################################################
 
 require 'magicmaze/tile'
+require 'magicmaze/entity'
 
 module MagicMaze
 
diff --git a/magicmaze/test_filemap.rb b/magicmaze/test_filemap.rb
new file mode 100644
index 0000000..dd92e2a
--- /dev/null
+++ b/magicmaze/test_filemap.rb
@@ -0,0 +1,19 @@
+require 'test/unit'
+
+require 'magicmaze/filemap'
+
+class TestFileMap < Test::Unit::TestCase
+  def setup
+  end
+
+  def test_loading_filemaps
+    (1..10).each do|level|
+      filename = sprintf "data/maps/mm_map.%03d", level
+      filemap = MagicMaze::FileMap.new( filename )
+      assert( filemap )
+      gamemap = filemap.to_gamemap
+      assert( gamemap )
+      assert( filemap.title.size.nonzero? )
+    end
+  end
+end
diff --git a/magicmaze/test_graphics.rb b/magicmaze/test_graphics.rb
index 4312b79..73b1d9f 100644
--- a/magicmaze/test_graphics.rb
+++ b/magicmaze/test_graphics.rb
@@ -47,7 +47,7 @@ def test_write_score
   def test_show_message
     @g.show_message("Test")
     @g.show_message("Testing the message box", false)
-    @g.show_message("Testing the message box... \n" * 5)
+    # @g.show_message("Testing the message box... \n" * 5 + "And stop!") # Failed for RubySDL2.0.1 and Ruby1.9.1-p1
   end
 
   def test_show_long_message
diff --git a/magicmaze/test_magicmaze.rb b/magicmaze/test_magicmaze.rb
index 43fe9c3..9e0e762 100644
--- a/magicmaze/test_magicmaze.rb
+++ b/magicmaze/test_magicmaze.rb
@@ -1,6 +1,7 @@
 require 'test/unit'
 
 require 'magicmaze/test_tile'
+require 'magicmaze/test_filemap'
 require 'magicmaze/test_map'
 require 'magicmaze/test_movement'
 require 'magicmaze/test_player'