[Rails] Why am I getting "undefined local variable or method `acts_as_taggable'"?

[softwareengineer 99]

Hello,
  
  I recently installed  acts_as_taggable using the following command:
  
gem install acts_as_taggable
# output follows
Attempting local installation of 'acts_as_taggable'
Local gem file not found: acts_as_taggable*.gem
Attempting remote installation of 'acts_as_taggable'
Updating Gem source index for: http://gems.rubyforge.org
Successfully installed acts_as_taggable-1.0.4
Installing RDoc documentation for acts_as_taggable-1.0.4...
  And added the following line to environment.rb
  require_gem "acts_as_taggable-1.0.4"
  
  However when I add the following to my target class (resource.rb):
  acts_as_taggable
  
  I get the following error 
  
undefined local variable or method `acts_as_taggable' for Resource:Class

Why am I getting this error and how can I fix it? My installation seemed to have gone OK so what am I missing here?

I have been searching everywhere and any pointers are greatly appreciated.

Thanks
Frank

  
  

		
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