ipython prompt does not appear in windows

[rusi]

If I use ipython under emacs on linux it works (at least basic REPL)
ie I can type an expression and I get a result followed by a prompt

On windows ipython works at the shell.
Plain python works in emacs as well.

But inside emacs I dont see a prompt in ipython although I see it in
python.
I have to type an expression and then the prompt appears.

Any clues?