Form_Validation Config file not working

[eluser]LairdWirli[/eluser]
I have the same problem:
Message: Undefined variable: config
after I moved the validation rules to (application/config/form_validation.php).

I am happy that you found a work around. It doesn't work in my case and I assume there has to be a different/official solution to the problem, since it is described in the official user guide.