Help, weird global variable + load problem

ruby-talk
1

We have a script starting with:

#!/usr/bin/ruby -w
require 'cgi'
cgi=CGI.new("html4")
begin
   $load_path = nil
   load 'conf.rb'
   load 'create_vars.rb'
   (...)

Which generates the error:

./create_vars.rb:1:in `load': string contains null byte (ArgumentError)

This is the line in create_vars.rb that generates the error:

load $load_path + 'lib/name_string.rb'

The global variable $load_path is assigned a value in conf.rb. The error is
inexplicably fixed by inserting arbitrary code between the two load
commands:

require 'cgi'
cgi=CGI.new("html4")
begin
   $load_path = nil
   load 'conf.rb'
   b=cgi
   load 'create_vars.rb'

where "b=cgi" can be *any* code you think of; it magically makes the error
go away and restores the value of $load_path that is assigned in conf.rb.

Other details:
This code runs on an Athlon-64 with Gentoo Linux. Programming in Ruby has
been a lot of fun ever since we ditched mod-ruby (restarting Apache every
time we change a class definition? Geez). However, getting errors like
this one gives me a headache.

Any ideas, besides leaving the bogus "b=cgi" code in?

thanks,
Pascal