On my WAMP box, I did the following:
Foo
If you're using a linux server for your application then it is necessary to use lowercase file name and class name to avoid this issue.
Ex.
Filename: csvsample.php
class csvsample {
}
In Windows, capitalization in paths doesn't matter. In Linux it does.
When you autoload, use "Foo" not "foo".
I believe that will do the trick.
I think it works when you take it out of autoloading because codeigniter is smart enough to figure out the capitalization in the path and classes are case independent in php.
I had a similar issue when deploying from OSx on my local to my Linux live site.
It ran fine on OSx, but on Linux I was getting:
An Error Was Encountered
Unable to load the requested class: Ckeditor
The problem was that Linux paths are apparently case-sensitive so I had to rename my library files from "ckeditor.php" to "CKEditor.php".
I also changed my load call to match the capitalization:
$this->load->library('CKEditor');