multi-level subfolders for controllers for 1.7.1

[eluser]xerobytez[/eluser]
Awesome snippet, this is exactly what I need. But I'm getting this error when trying to use it.

A PHP Error was encountered
Severity: Notice
Message: Undefined offset: 0
Filename: core/MY_Router.php
Line Number: 43

Line 43:

Code:

} while (is_dir(APPPATH . 'controllers/' . $dir . '/' . $segments[0]));

Anyone have any ideas? Trying to use this with CodeIgniter 2.0

Thanks