Description:
------------
Calling session_destroy() after call to session_regenerate_id() results in the failed session destruction and the following warning:

Warning: session_destroy() [function.session-destroy]: Session object destruction failed...

If I remove the call to session_regenerate() then session_destroy() works correctly.

Reproduce code:
---------------
<?php

ob_start()

session_start();

//some code

session_regenerate_id(true);

//some code

session_destroy();

ob_end_flush();

?>

Expected result:
----------------
Session should be destroyed

Actual result:
--------------
Warning: session_destroy() [function.session-destroy]: Session object destruction failed...