Form validation won't call the callback function

[eluser]xarazar[/eluser]
Hi guys,
I don't know what happened but I'm facing some bizarre behaviour of the form_validation class. The callback function in the code below simply doesn't work (it's not getting called).
It's a simple MVC setup (not HMVC).
Both methods are in the same class.
I tried adding My_Form_validation like so:

Code:

class MY_Form_validation extends CI_Form_validation{
    
    function run($module = '', $group = ''){
        (is_object($module)) AND $this->CI = &$module;
            return parent::run($group);
    }
    
}

according to suggestions in some post on the forum and it partly works (the callback function is triggered).

But in a simple MVC system I shouldn't be forced to do that, should I?
Anybody any ideas?

Many thanks