They don't list it doesn't mean it won't work, as I am using my Gen ONE iPod touch with it with iOS 3.x.x and still works fine. I think they only did that for legal reasons.
Here are additional info that might interest you:
Japanese site: http://venturecraft.jp/gadget_jp/sdt/index.php
Buying site: http://venturecraft.jp/gadget_en/buy_paypal.php
Thanks for your infor.
Does SDT allow Line Out? Can I use external amp with SDT?