strange routing error? Autoload not being called on some 404's.

[eluser]gRoberts[/eluser]
autoload.php

Code:

$autoload['helper'] = array('url');

error_*.php

Code:

<? include(APPPATH . '/views/common/header.php'); ?>
                <div class="item">
                    <h2>&lt;?= $heading; ?&gt;</h2>
                    <p>&lt;?= $message; ?&gt;</p>
                </div>
&lt;? include(APPPATH . '/views/common/footer.php'); ?&gt;

header.php

Code:

<img src="&lt;?= base_url(); ?&gt;assets/images/logo.png" alt="Company name" title="Company name" />

Theres not really much to see.

Cheers