As reported by Ondrej Certik on the IPython mailing list:

Here is how to reliably (100%) reproduce it in ipython 0.8.2 (the bug
indeed goes away in 0.8.4):

http://code.google.com/p/sympy/issues/detail?id=822

together with a screenshot how the terminal looks like (see the
comment #6 for the exact sympy revision to use). Maybe you could use
it to track the bug down in curses, as your patch only seems to be a
workaround (albeit working).

Ondrej

/quote

While unfortunately right now I don't have the time to try and whittle
this down to a smaller, self-contained example, it's great to at least
have a guaranteed reproducible way of triggering the bug.  It requires
installing specific versions of both ipython and sympy, but that's very
straightforward to do, as both are pure-python projects with no
dependencies outside the stdlib.