flexi auth - A user authentication library for CodeIgniter

[eluser]pinmouse[/eluser]
I just did a fresh CI install with Flexi Auth and tried to setup the Demo version via the Installation Guide, but when I go to my site (I'm setting it up on a live site), all I'm getting is the following error:

An Error Was Encountered
Unable to load the requested class: flexi_auth_lite

I've gone over the installation guide 10 times now and I'm quite sure I've done everything right. Any help would be greatly appreciated! Thanks!