You know what? 2 days ago I've bought original sleep cover, but today I finally received
http://www.ebay.ca/itm/Ultra-Slim-Sm...-/282218702583 this cheap cover. Just shipping was very slow, almost a month. But I like it more than original one so far. It fits better than original, no smell at all, sleep function works properly, it is slim and soft inside. I don't know is it durable or not, because front part is very thin, but for know I am quite happy with it and will return original cover.