Gandev is saying that the slot-2 card already has two games on it, the problem will be nothing to do with the ttds at all.
You should check that the games have copied correctly, maybe by testing the cart in a GBA or one someone elses DS. Try ang get your friend to copy the games again, see if that helps, he/she may have copied them wrong. Try booting the slot-2 card without the ttds in the ds maybe.
I do agree though, that a newer model slot-2 cart would be your best move, the EZ 3-in-1 is a good choice.