Error - info_controller.rb to define Rails::InfoController

Hi,

I am new to Ruby on Rails. I have developed a couple of small
applications from scratch and they are working fine.

I recently installed the source for an application developed by someone
else. When I run it, the Riding Rails page shows up fine. However, when
I click on the “About your application environment” link, I get the
following error:

Expected
D:/ruby/lib/ruby/gems/1.8/gems/rails-1.2.2/builtin/rails_info/rails/info_controller.rb
to define Rails::InfoController

I am unable to figure out what is wrong. Perhaps the same question has
been posed by others but I could not find anything that I could use to
resolve this problem.

Can someone please point me in the right direction to sort out this
problem?

Cheers,

Thewalker