Why do my leiningen's repl show too many prompt message?

D:\src>lein repl
nREPL server started on port 57504 on host 127.0.0.1
REPL-y 0.3.0
Clojure 1.5.1
    Docs: (doc function-name-here)
          (find-doc "part-of-name-here")
  Source: (source function-name-here)
 Javadoc: (javadoc java-object-or-class-here)
    Exit: Control+D or (exit) or (quit)
 Results: Stored in vars *1, *2, *3, an exception in *e

user=> (str "I don't want empty prompt!")
"I don't want empty prompt!"
user=>
user=> (println "Oh....")
Oh....
nil
user=>
user=> (exit)
Bye for now!

(screen shot is here. I want to paste here, but I have no 10 reputation, sorry)

You can look a needless empty prompt message like user=>. Of course, it is not needed, and I didn't push enter key.

I have two questions:

1. Is this behavior regular? (I am sure it is not!)
2. and if it is not regular, do you have solution of this problem?

My Environment:

• Windows 8 64bit (Japanese)

• paste lein -v

  Leiningen 2.3.4 on Java 1.7.0_21 Java HotSpot(TM) 64-Bit Server VM