Announcement If you make your GCTs using the GCT generator on the geckocodes.org website.. then STOP! It has been known for quite some time that the generator can (at random) botch your codes and/or botch the last compiled line of the GCT (the line which tells the code handler there are no more codes left). A lot of people still use the site to make GCTs, hence why this announcement is being made.
Here's the guide on how to make GCTs correctly using the Ocarina program (download of program also provided) - http://mkwii.com/showthread.php?tid=37