The problem about " [function.include-once]: failed to open stream"

help!!!English is poor,sorry!

I run wordpress locally with xmapp, and i code something in the function.php.

I just want to do this :
define(‘FW’,TEMPLATEPATH . ‘/framework/’);

and i can :
include_once(FW.’/.framework_init.php’);

But it problem :
Warning: include_once(C:\xampp\htdocs\wordpress/wp-content/themes…

So it means “FW” = “C:\xampp\htdocs\wordpress” ?

and another method to do this:
require_once(TEMPLATEPATH . ‘/framework/framework_init.php’);

it success~~ -_-||| Why? I don’t understand. I can’t find out the answer. Pleaes help me, thanks!