Script Summary: Compares your stamps collection with the collection of someone else
Copyright: 2009, w35l3y (http://gm.wesley.eti.br/includes/neopets)
License: GNU GPL
Your stamps are cached for 6 hours by default.
So it might take some time to update if you just added a new stamp to your collection.
I don't recommend, but if you want to disable caching then replace the line:
//GM_setValue("cache", 1 * 60 * 60 * 1000); // 1 hourto
GM_setValue("cache", 0); // disabled