The complete debate can be found here : http://www.shiachat.com/forum/topic/235045178-is-bahaullah-a-prophet/
I will just summarise the discussion. The original poster by the name of Hamzah wanted to start the discussion on weather Bab and Baha’u’llah are true prophets or not. His main point of contention was that the muslim claim of finality of Prophethood is to be interepreted as Coming of New Prophethood. For substantiating his claim he brings proofs from Bible.
Then another lady(farhana.jaffer) questions Hamzah as to why Ghulam Ahmed Qadiani cannot be considered a Prophet by their own interpretation. He(Hamzah) answers that Prophets need to be measured by his fruits. The argument was rebutted by another member Abal Faadhil who raised the issue of Prophet Sheesh (peace be upon him), who lived in dissimulation and did not contribute much.
Then there were discussions on the term Khatemiyat ( seal of Prophethood) and excommunication by the UHJ.
During the course of the discussion Hamzah agreed there were some fallacies in his faith and would study the faith more to get answer for the queries raised by the other members of the forum.