I just had another "live chat" with the Villa Fortuna support and they confirmed once again that they do indeed accept players from the U.S. with the exception of the normal Microgaming restricted states.
I'm not sure why you'd be having problems here so I will follow up on this with their managers and hopefully get to the bottom of this.
Meanwhile, if you are not in a restricted state and are having problems registering, check with their live chat support and they may be able to get you playing.
Thanks,
NDN