I am using Idle 1.2.2. (python 2.5.2.)
This is IDLE's behavior, not really python's. Anyway, I don't really
mind the minor annoyance as you don't seriously program serious
program in interactive mode (no pun intended). Anyway, if you feel
really disturbed by this, you should file a bug in: http://bugs.python.org/
There's a free version of Wing IDE that has an IDLE-like interface
that doesn't have this issue...or you could just use the command line
version of IDLE.
Mike