I agree with arashi. The only reason Julia and Barnabas recognized Gerard, Daphne, and Roxanne was because they had seen the ghosts of the two former in the present, and Roxanne was recognized by Barnabas because she was his love interest at the time.
What's funny about this is that Barnabas and Julia recognize Angelique, no matter what time she is in. With the exception of Cassandra, whom I believe Barnabas suspected was Angelique from the get go, Angelique seemed to be the only one that they recognized in every time period she was in.