Ok, I put my newly bought dstwo into my 3ds, (latest firmware), it doesn't show up, I use a friends 3ds with an old firmware to update it to work, It shows up, I update it, it succeeds. I tae it out, delete the update file, put it in my 3ds, doesn't show up. This was happening with my old dstwo when I updated the firmware of my 3ds. So it's probably not a contact error. Other ds and 3ds games work. I've tried blowing. Please help. EDIT: this might not be a defect as my old dstwo had this problem when I updated my 3ds. The problem might of stuck.