function simple_access_form error

the function causes an error on line 148-149 of simple_access.module if the user doesn't have access permissions to the module:

 $simple_access_form = simple_access_form($form['#node']);
 $form = array_merge($form, $simple_access_form);

because the simple_access_form function returns null so the array_merge barfs.

You could solve it by returning array() from simple_access_form on the last line (i.e., if perms are inadequate for the module), or by replacing the above lines with:

 if ($simple_access_form = simple_access_form($form['#node']))
    $form = array_merge($form, $simple_access_form);