helper -> call to undefined function

Greetings.
I have hit a wall here guys.
My app works just fine at localhost, but the most strange thing is happening after I uploaded it to a host.
Here's the scenario:
In my BaseController I have assigned the $helpers var with the helpers to be autoloaded:

Code:

protected $helpers = ['form', 'mylib'];

Inside app\Helpers is the correspondent file: mylib_helper.php
However, my script crashes with the error "call to undefined function", which is a function that exists inside my helper file.
I've tried also to extend my helper, changing its name to form_helper.php, since the form helper is loading just fine, as any native helper in the framework. Only my custom helper doesn't load.
Any thoughts?
Thanks for listening.