I received my 3 bead today, and the exact same thing happened to me. Worst part is the little lock piece fell out of sight and is now lost in the ether of my kitchen floor. Spent a while looking for it but no luck. Though even if I did find it and manage to pop it back in, not sure I'd trust it to stay attached to my watch. Blargh.
Ditto - http://i.imgur.com/h6cq2mm.jpg