I too was facing the same problem.
Page template attribute was not showing up for the custom theme.
I found that this was happening because the custom theme did not have any custom template.
A custom template will have a header entry like :
Template Name: Archieves, as in archieves.php
<?php
/**
* @package WordPress
* @subpackage Default_Theme
*/
/*
Template Name: Archieves
*/
?>
The default theme has two custom templates :
Archieves.php
Liks.php
Hope this helps further.
