diff --git a/app/controllers/simple_captcha_controller.rb b/app/controllers/simple_captcha_controller.rb
index 4358c32..62a8afa 100644
--- a/app/controllers/simple_captcha_controller.rb
+++ b/app/controllers/simple_captcha_controller.rb
@@ -5,8 +5,9 @@ class SimpleCaptchaController < ActionController::Metal
   # GET /simple_captcha
   def show
     unless params[:id].blank?
-      send_file(
-        generate_simple_captcha_image(params[:id]),
+      image = File.read generate_simple_captcha_image(params[:id])
+      send_data(
+        image,
         :type => 'image/jpeg',
         :disposition => 'inline',
         :filename => 'simple_captcha.jpg')
diff --git a/lib/simple_captcha/form_builder.rb b/lib/simple_captcha/form_builder.rb
index 4bec7a7..8624f7e 100644
--- a/lib/simple_captcha/form_builder.rb
+++ b/lib/simple_captcha/form_builder.rb
@@ -26,7 +26,9 @@ def template
         end
         
         def simple_captcha_field(options={})
-          text_field(:captcha, :value => '', :autocomplete => 'off') +
+          text_field_options = {:value => '', :autocomplete => 'off'}
+          text_field_options[:size] = options[:size] unless options[:size].nil?
+          text_field(:captcha, text_field_options) +
           hidden_field(:captcha_key, {:value => options[:field_value]})
         end
     end
diff --git a/lib/simple_captcha/image.rb b/lib/simple_captcha/image.rb
index 62deed5..81c45c7 100755
--- a/lib/simple_captcha/image.rb
+++ b/lib/simple_captcha/image.rb
@@ -48,6 +48,7 @@ class Tempfile < ::Tempfile
       # Replaces Tempfile's +make_tmpname+ with one that honors file extensions.
       def make_tmpname(basename, n)
         extension = File.extname(basename)
+        n ||= 0
         sprintf("%s,%d,%d%s", File.basename(basename, extension), $$, n, extension)
       end
     end