Error requiring action_mailer - "Text is not a module"

[Pablo Q.]

[Note: parts of this message were removed to make it a legal post.]

Does anyone have gotten this error?

require 'action_mailer'

C:/ruby/lib/ruby/gems/1.8/gems/actionmailer-2.1.0/lib/action_mailer/vendor/text-format-0.6.3/text/format.rb:49:
Text is not a module (TypeError)