Server won't start with ActiveMerchant

Hi,

Everything was working fine until I went to use ActiveMerchant. Have spent a few hours trying to figure this out with no success.

Here's the error I'm getting

** Starting Rails with development environment... Exiting /Library/Ruby/Gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:445:in `load_missing_constant': uninitialized constant ActiveMerchant (NameError)

And in environment.rb I have

unless RAILS_ENV == 'production'     PAYPAL_ACCOUNT = 'sandboxaccount@example.com'     ActiveMerchant::Billing::Base.mode = :test   else     PAYPAL_ACCOUNT = 'paypalaccount@example.com'   end

Appreciate anyone kind enough to help me out. Can't get my head around this and holding me back.

Cheers

Lee,

Do you need to have a require statement in environment.rb?

    require 'active_merchant'

Al