custom theme template.php assigning node-form.tpl.php breaks module functionality

I am having trouble getting this to work on my theme. It works fine on Garland, however.

After troubleshooting I see that calling the below code in template.php breaks dependent fields.
Removing the code allows functionality to work perfectly on my theme, but I am unable to customize the profile-node-form page without using the .tpl.php

From template.php:

function mytheme_theme() {
  return array(
    'profile_node_form' => array(
      'arguments' => array('form' => NULL),
      'template' => 'profile-node-form',
    ),
  );
}

Could anyone give me any pointers on this issue? I appreciate it.