Require stops working

Hi,

I have encountered a problem where the require statement seems to fail 
after several page loads. Below is a simple set of scripts to 
demonstrate this issue. I'm using Apache/2.0.54 on Ubuntu Breezy with  
libapache-ruby1.8 (1.2.4-1), libapache2-mod-ruby (1.2.4-1), liberuby 
(1.0.5-1).

== test.rhtml ==
<%
require 'test'
puts "test.rhtml"
%>
== test.rb ==
puts "test.rb"
== (end of file) ==

After placing these files in the same directory and viewing test.rhtml 
in a browser, the expected output is "test.rb test.rhtml". I receive 
that output for about five page loads. Then, the output changes to just 
"test.rhtml". It appears that the parser stopped requiring test.rb.

Any ideas as to why this occurs?

Ben