I am really puzzled by the confusion that remains here. First, people need to know that the term prophet is used in two ways by the LDS. In essence, any individual who is given revelation which is pertinent to the future is acting prophetically. Thus, any individual (in or out of the Church) might prophecy and thereby be referred to as a small-'p' prophet. However, some individuals are formally ordained (by laying on of hands) as Prophets, Seers, and Revelators. Thus, Brother Jones may be a Bishop, a High Priest, an Apostle, and a Prophet at the same time (we actually have 15 prophets if you wish to pursue the issue). Unique to the LDS belief is the understanding that the authority of Priesthood offices are retained, based on worthiness, forever. So while Joseph Smith acted prophetically, he also held the titles of, Elder, Apostle, Prophet, President, and High Priest. It could also be said he was a Deacon, a Teacher, and a Priest. These are titles. In fact, broken down by office and (common usage)

Aaronic (preparatory) Priesthood
Deacon (Brother Jones) 
Teacher (Brother Jones)
Priest (Brother Jones)
Bishop (Bishop Jones)

Melchizidek Priesthood 
Elder (Elder Jones)
Seventy (Elder Jones)
High Priest (Brother Jones)
Patriarch (Formerly Patriarch Jones, new policy recommends Brother Jones) 
Apostle (senior Quorum member designated Prophet, or President Jones)

 

Consider this fact. Joseph Smith's father served for years as the Patriarch of the Church. While he was a patriarch (speaking of his role as a father) it would sound silly to state that Joseph Smith Sr. was the (small 'p') patriarch of the church.

Joseph Smith, while a 'p'rophet, was also a 'P'rophet by virtue of Priesthood office. Thus Pope John Paul, President Obama, Prophet Smith (though the term President Smith is more commonly used). So feel free to refuse to identify Joseph Smith as a 'p'rophet. But it is insensitive to both the RLDS and the LDS and erroneous to ignore the fact Joseph Smith was a 'P'rophet (an office in the High Priesthood). I don't follow the Pope, but I wouldn't deny he is one. You don't have to believe Smith was a prophet, to accept he was a Prophet in the LDS Priesthood.