For some reason, my 16gb Transcend card showed as unformatted on the N800s file manager when I had kmplayer installed. Other than that, I've used it to ferry large files between computers, and even to back my PS3 up onto, and it's been perfect, with >10mbps speeds at all times. I use an 8gb Transcend card in my Canon Powershot with no problems too. I think you guys with problems were just cursed with a bad batch.