I have a similar issue. I have a report server that will not start, saying a report server with the same name already exists in the network, we only have the one application server, i deleted the report server with the deletecomponent command, I then ran rwdiag.sh -FindAll and the report server is still listed.
Does the Application Server have to be restarted every time a change like this occurs?
it is very likely that the reports server process is still running and that is the cause why you are getting that error. I am not sure your platform but you can run on unix "ps -ef | grep rwserver" and see if the old standalone reports server is there. Kill -9 it.