If you have not loaded the tt menu you will have the freezing problem, or the menu with the happy face that appears when successfully loading will be a sad face instead. You must load the DS TT Menu onto the chip, and make sure it is the latest from the DS TT site. This is their web address,

http://www.ndstt.com/download.html

and they not only have the updated menu with fix, they have some basics on how to tell if you have a piece of crap: however, it is usually that people just need the menu but were never told, or that they have the old software or software foranother chip (e.g. the R4DS). Don't despair. And check out espalnds.com and espalzone.com in addition to romulation site (mentioned below) - the site is in spanish but more up to date. If you don't speak Spanish, use the BabelFish translator at AltaVista to help.