Changed \w in sanitize_filename to A-Za-z0-9 in order to be less generalizing

lib/technoweenie/attachment_fu.rb

@@ -378,7 +378,7 @@ module Technoweenie # :nodoc:
             name.gsub! /^.*(\\|\/)/, ''
 
             # Finally, replace all non alphanumeric, underscore or periods with underscore
-            name.gsub! /[^\w\.\-]/, '_'
+            name.gsub! /[^A-Za-z0-9\.\-]/, '_'
           end
         end