Not Erasing your game saves from your carts before selling your game. Not a huge deal right? It is if the next owner is a gaijin who can't read Japanese and spends 20 minutes trying to erase all the save data in Twin Bee Rainbow bell Adventure because I can't read Japanese. That's not the only game that I had trouble with, Kirby Superstar took me a while to erase the save data, Kirby 64 at least had a bomb to signify ERASE SAVES. Super Bomberman 5 took me a few minutes too. Not cleaning your games. Most of the time, I clean the contacts and I'm good to go. BUT Kirby super star was FILTHY Gunk in every Crevas of the cart, the back label missing, dirt EVERYWHERE, a hair, A HAIR stuck where the Contacts are coming out that took forever to dig out with a Q tip. Had to use a lot of Alcohol to clean it and almost resorted to goo gone. What slob owned this game before I did? When I buy games from Japan, I expect them to be pristine, But between that and the Salamander Deluxe that was disc rotted, maybe they aren't as clean as I thought. So that's what I have SO FAR. Lets see what else comes up.