Help: _lang and config-files are dispayed instead of included

[eluser]peterphp[/eluser]
My problem is that files like

project_lang.php or form_validation.php

are not properly included by CI, instead the *content* of these files is output to the browser (at the top of my html pages).

I am hosting with Rackspace Cloud.

CI-Version: 1.7.2

I created a very basic test controller:

Code:

function index()  // provides the test page
    {
        $this->lang->load('test', 'english');
        $this->load->view('test_view');

    }

and just a 'Hello world' view.

The output of this is the whole content of the test_lang.php file, followed by my 'Hello world' string from the view.

The same happens as soon as I load the form_validation library:

$this->load->library('form_validation')

This outputs the whole content of the

application/config/form_validation.php

file.

Any help or idea is highly appreciated.

Thanks!