debugger problem on windows xp

[Rand Waltzman]

I am new to Ruby and have just tried using the debugger for the first
time. Unfortunately, the result is nothing like I expected. Here is
the first part of session:


C:\ruby\ruby4rails>ruby -r debug c2fi.rb
Debug.rb
Emacs support available.

c:/ruby/lib/ruby/site_ruby/1.8/ubygems.rb:10:require 'rubygems'
(rdb:1) step
c:/ruby/lib/ruby/site_ruby/1.8/rubygems.rb:10:require 'rbconfig'
(rdb:1) step
c:/ruby/lib/ruby/1.8/i386-mswin32/rbconfig.rb:5:module Config
(rdb:1) step
c:/ruby/lib/ruby/1.8/i386-mswin32/rbconfig.rb:7: raise "ruby lib
version (1.8
4) doesn't match executable version (#{RUBY_VERSION})"
(rdb:1) step
c:/ruby/lib/ruby/1.8/i386-mswin32/rbconfig.rb:9: TOPDIR =
File.dirname(__FILE__
).chomp!("/lib/ruby/1.8/i386-mswin32")
(rdb:1) step
...

Why doesn't it just start executing the statements in c2fi.rb (a simple
program to convert Celsius temperature to Fahrenheit - I got it out of
the book Ruby for Rails by David Black - the program runs just fine)?
Why is it showing all these "require" statements that are not in the
program? The line

c:/ruby/lib/ruby/1.8/i386-mswin32/rbconfig.rb:7: raise "ruby lib
version (1.8
4) doesn't match executable version (#{RUBY_VERSION})"

is particularly disturbing. Does this mean that there is something
wrong with the installation?

I am running the following version of Ruby:

C:\ruby\ruby4rails>ruby --version
ruby 1.8.4 (2006-04-14) [i386-mswin32]

Any help on this will be greatly appreciated.

Rand Waltzman