why is idle configured as idle -n in the kde menu?

[Tim Richardson <tim@tim-richardson.net>]

 I'm starting to learn python to learn pyqt.
I was very confused because idle crashes the second time a qt program is 
executed.
The solution is to run idle from a console, or use the kde menu editor 
to remove the -n option.
(http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=601610)

Why is idle configured as
idle -n
in KDE?