Custom callback function in form validation not working

[eluser]LuckyFella73[/eluser]
Your class extending the form_validation class must be
saved in application/libraries and have the filename: "MY_Form_validation.php"
unless you did set up an other prefix in your config file.

In your class "MY_Form_validation" there is no need to load the form_validation
class! your class will be merged automatically when loading the form_validation class