I had this problem with fcart and the developers told me to add this code snippet at the top of the page - I believe it will also work for xcart. The idea is that it preserves your session id when moving outside xcart as such - it certainly works for fcart
Code:
<? session_register("id") ?>
Insert that snippet at the top of your standard html page and then rename your page filesomething.php
Hope this helps
quote for today: get on your bike !!