No such file load errors - md5

Dear All ,

I have a problem with : this error messasge " No Such File Load error -
md5 "

I can only use with development section.(rails s)
I can’t use with production . ( rails s -e production). I use this
command, the error message is like this

Exiting
/opt/local/lib/ruby1.9/gems/1.9.1/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:317:in
rescue in depend_on': No such file to load -- MD5 (LoadError) from /opt/local/lib/ruby1.9/gems/1.9.1/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:312:independ_on’
from
/opt/local/lib/ruby1.9/gems/1.9.1/gems/activesupport-3.2.2/lib/active_support/dependencies.rb:225:in
require_dependency' from /opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/engine.rb:439:inblock (2 levels) in eager_load!’
from
/opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/engine.rb:438:in
each' from /opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/engine.rb:438:inblock in eager_load!’
from
/opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/engine.rb:436:in
each' from /opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/engine.rb:436:ineager_load!’
from
/opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/application/finisher.rb:53:in
block in <module:Finisher>' from /opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/initializable.rb:30:ininstance_exec’
from
/opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/initializable.rb:30:in
run' from /opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/initializable.rb:55:inblock in run_initializers’
from
/opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/initializable.rb:54:in
each' from /opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/initializable.rb:54:inrun_initializers’
from
/opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/application.rb:136:in
initialize!' from /opt/local/lib/ruby1.9/gems/1.9.1/gems/railties-3.2.2/lib/rails/railtie/configurable.rb:30:inmethod_missing’
from /Users/workstation02/sportskaki/config/environment.rb:5:in <top (required)>' from /Users/workstation02/sportskaki/config.ru:4:inrequire’
from /Users/workstation02/sportskaki/config.ru:4:in block in <main>' from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:51:ininstance_eval’
from
/opt/local/lib/ruby1.9/gems/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:51:in
initialize' from /Users/workstation02/sportskaki/config.ru:1:innew’

…x…

to encrypt password using with require ‘md5’ , require digest/md5 , in
my controller , I declare head of my controller

require digest/md5
Class Manage::AdminusersController < ApplicationController
def index
@adminusers = Adminuser.all
end
end …

And I run rails s -e production , I see no such file to load md5.
I remove require digest/md5 , I see this error also.

In my project I use
rails 3.2.2 and
ruby 1.9.3p125 (2012-02-16 revision 34643) [x86_64-darwin11]

Pls help me, all

Sincerely

phoesan