Nodelet topic connection problem

Hello everybody, I have a little question for you. I am trying to use the navigation part of the rtabmap package but I am not able to connect topics to some nodelets. with camera=artemis/navCam The disparity and the camera_info topic are publishing information and seem to work fine but the disparity2cloud nodelet don't suscribe to them. I don't understand why the remapping is not working. (I guess that I have forgotten something but I really don't know what) Thanks in advance.