Neither ruby and nor irb can load .rb file in current directory

Question

I'm having a really noob problem with importing files in Ruby. I'm making a Ruby app in Windows XP. All the class files for the app are in "C:/Documents/Prgm/Surveyor_Ruby/lib". But when I require a file in another file, neither ruby nor irb can find the required file.

The current directory's contents:

C:\Documents\Prgm\Surveyor_Ruby\lib>dir
 Volume in drive C has no label.
 Volume Serial Number is AAAA-BBBB

 Directory of C:\Documents\Prgm\Surveyor_Ruby\lib

10/09/2010  06:32 PM    <DIR>          .
10/09/2010  06:32 PM    <DIR>          ..
10/08/2010  03:22 PM             5,462 main (commented).rb
10/08/2010  03:41 PM                92 question.rb
10/08/2010  09:06 PM             2,809 survey.rb
10/09/2010  06:25 PM               661 surveyor.rb
10/08/2010  01:39 PM             1,546 test.rb
               5 File(s)         10,570 bytes
               2 Dir(s)  40,255,045,632 bytes free

Confirmation that irb is in correct directory:

C:\Documents\Prgm\Surveyor_Ruby\lib>irb
irb(main):001:0> Dir.pwd
=> "C:/Documents/Prgm/Surveyor_Ruby/lib"

...yet irb can't load survey.rb:

irb(main):002:0> require 'survey'
LoadError: no such file to load -- survey
        from <internal:lib/rubygems/custom_require>:29:in `require'
        from <internal:lib/rubygems/custom_require>:29:in `require'
        from (irb):2
        from C:/Ruby192/bin/irb:12:in `<main>'

Answer 1

None of these worked for me, but this did:

irb -I .
>require 'file'
 => true