Problem with my rails 2.2.2

I have installed rails 2.2.2.when i created my rails project with
version 2.2.2
its throwing error

Missing the Rails 2.2.2 gem. Please gem install -v=2.2.2 rails, update
your RAILS_GEM_VERSION setting in config/environment.rb for the Rails
version you do have installed, or comment out RAILS_GEM_VERSION to use
the latest version installed.

but in my machine rails 2.2.2 is installed

what does “rails -v” give you?
what’s in your environment.rb?