All orders placed before the new rating system came into place have received automatic .5 stars for me. About 15 today have come through like that. They are not registered on my gig page as being .5 stars but they are registered in the system. I have dropped from 5.0 to 4.8 for one gig as a result! You should check out your orders too.
Another aspect of the "roll out"
See this discussion, Ryan