Using ActiveRecord on MacOS X.

I'm trying to use ActiveRecord on the latest MacOS X Tiger, but it
gives me this error when I try to instantiate my subclass of
ActiveRecord::Base (after calling establish_connection)

Here's my small code snippet:

require 'rubygems'
require_gem 'activerecord'

ActiveRecord::Base.establish_connection(
:adapter => 'sqlserver',
:database => 'ETT',
:mode => 'ODBC',
:dsn => 'Dev',
:username => 'ETT_sa',
:password => 'MR#Fko[!Iu',
:host => '192.168.97.227'
)

class Order < ActiveRecord::Base
end

an_order = Order.new
an_order.name = "Dave Thomas"
an_order.email = "dave@pragprog.com"
an_order.address = "123 Main St"
an_order.pay_type = "check"
an_order.save

The appropriate database exists and ODBC DSN is configured. I
installed DBI several times and it is there, but can't find it.

Here is the error:

csh: /sw/bin/init.cs: No such file or directory.
RubyMate
Ruby

Theme:
RubyMate r4913 running Ruby v1.8.4 ()

ar.rb

MissingSourceFile: no such file to load - dbi

method require__ in custom_require.rb at line 21
method require in custom_require.rb at line 21
method require in dependencies.rb at line 147
method require_library_or_gem in requires.rb at line 7
method silence_warnings in reporting.rb at line 11
method require_library_or_gem in requires.rb at line 5
method sqlserver_connection in sqlserver_adapter.rb at line 23
method connection_without_query_cache= in connection_specification.rb
at line 251
method connection= in query_cache.rb at line 54
method retrieve_connection in connection_specification.rb at line 220
method connection in connection_specification.rb at line 78
method columns in base.rb at line 696
method attributes_from_column_definition in base.rb at line 1969
method initialize_without_callbacks in base.rb at line 1351
method initialize in callbacks.rb at line 236
at top level in ar.rb at line 17
Program exited.