Problem loading custom library

[eluser]frost9928[/eluser]
Hi guys,

I'm having a problem getting a library to load. I have a total of three libraries that are add-ons to the base CI system. The first one is an access control library. It loads and works just fine. The second is a library to calculate sales tax. It won't load no matter what I do. It's structure is as follows.

taxcalc.php

Code:

<?php
class Taxcalc extends Controller {

   function Taxcalc() {
       parent::Controller();
   }

   function get_state_tax(zip) {

   }
}
?>

The above structure is the same for the access control library which does work and is also the same for the UPS shipping library which doesn't work either. Each file has been placed in the /system/application/libraries folder with lowercase file names and upper cased class names as is CI standard.

I'm loading them with:

Code:

$this->load->library('taxcalc');

And trying to access them with:

Code:

$this->taxcalc->some_function();

Can anyone tell me if I'm doing something wrong or if I may have a problem with my CI install.

Thanks