Name a game from a really popular video game franchise that behaves like a piece of shareware on the Nintendo DS. Stumped? The answer would be a pirated copy of Final Fantasy: Crystal Chronicles.
Stumped even more? Now, if you are an owner of a R4DS, M3, TTDS, or whatever Slot-1 flashcart with a fancy acronym for a name, you would probably be in for a surprise should you play the ROM (a.k.a pirated) version of Final Fantasy: Crystal Chronicles.
According to a commentor on this particular GoNintendo post, the guys at Square Enix probably built in some form of copy protection into the game which checks the game's file size from time to time. Since Slot-1 flashcarts require ROMs to be DLDI-patched, the patching process actually alters the ROM's file size.
In the case of Crystal Chronicles, the copy protection will trigger a "Thank you for playing!!" page after 10 minutes of play with the pirated ROM on a Slot-1 flashcart. Smart readers would probably realize that this doesn't affect Slot-2 users at all.
Now, pirates being pirates, they are actually a really persistant bunch. Apparently there's now a solution to the problem. The guys at FR actually highlighted a tool (which I think patches the game) and a little bit of Googling wouldn't hurt your chances of finding that site.
Anyways, my advice would be to get the original game. Saves you a whole lot of trouble, and it's guaranteed to work, unlike the pirated one. The original Final Fantasy: Crystal Chronicles is available at Play-Asia for USD 44.90. Click here for further details.