[eluser]stormbytes[/eluser]
I always hated the "MY_controller" convention for such basic functionality. There should be a login class buit-in to CodeIgniter. How the development team would force users to tap dance around such an obvious oversight is mind boggling.
FWIW: I created a 'login' library which is autoloaded. User logged-in checks are done in constructor method, and any required user vars are made available via $CI->load->vars().
I find this infinitely easier then having to remember to use MY_Controller.