Can't access to my wl-hdd

Hello.

Today i received my wl-hdd box. I can go to the configuration pannel but i can't connect with FTP or with another PC to the file.

But i haven't put a hard drive in the wl-hdd, just an usb key of 2G in the USB port, and in the configuration pannel i have choose, "share USB".

Why i can't connect and see files on my USB key and why my PC doesn't detect the wl-hdd box ? Only because i haven't put a hard drive ?

Sorry for my english but i'm french and it's very hard :s.