I am finding that it's like that for all the mixes uploaded onto Yousendit, not just the ones you've been uploading, Lottie. Maybe it would be good to wait and see if other users are having this problem, before you go to the effort of uploading more choonage.
I mean, registering is not such huge deal at the end of the day, but it's just weird that literally from one hour to the next Yousendit went from being open-access to anyone that clicked on one of the link posted here, to requiring registration. Or maybe Yousendit just doesn't like me!