one spot, i believe, was at cleveland clinic. however, take all this with a grain of salt. unfilled spots are much more an indication of poor planning and failures in "match strategy" by the department than the overall quality of the program or lack of over-qualified applicants who would die to land a spot there.
This is true, but programs also sometimes purposely don't rank everyone, because they know they'll have the pick of the unmatched if they don't find "the perfect resident" through the match.