Simple Controler/Class naming problem

[eluser]seismic[/eluser]
Hi there, please help me. I have the problem with the naming:

I have the controler with the name: test.php (in its folder controllers)

Code:

<?php
class Test extends Controller {
function index() {
  echo 'Test CI. This is class Test;
}
}
?>

What we know the naming rule is:
name of the class -> First Letter Uppercase
name of file -> all Lowercase.

Anyway, putting the link: www.example.com/index.php/test <- it doesnt works. Ive tried also www.example.com/test (it opens the main site : www.example.com)

I doesnt works until i change the controller name to Test.php (So first letter uppercase like in the name of class in the file)
then it works with www.example.com/index.php/Test

Of course it doesnt work even the name of class is lowercase: 'class test' -> www.example.com/index.php/test <- this also doesnt works

Does anyone khave the idea where the bug could be located, how to fix this problem?