Frog CMS

Hi there,
I have an external script placed in the root of the website that creates a session with some variables.

The problem is that when I do this in Frog:

<pre>
<?php session_start(); print_r($_SESSION);
?>
</pre>

I only get these empty arrays:

Array
( [framework_flash] => Array ( ) [frog_auth_user] => Array ( [username] => admin )
)

What should I do?
It seems that Frog destroys sessions created externally.
Is it right or am I missing something?

Thanks!!