TNS-01106: Listener using listener name LISTENER has already been started

You are trying to start listener for a database and it is getting stopped and you are getting following error

TNS-01106: Listener using listener name LISTENER has already been started

This error occurs mainly because more than two listener is running on same port.

So stop one of the listener ,more about this has been explained in the following post

http://forums.oracle.com/forums/thread.jspa?threadID=366499