Brett C. just today pushed
http://hg.python.org/cpython/rev/556b9bafdee8
changeset: 76310:556b9bafdee8
user: Brett Cannon <brett@python.org>
date: Sat Apr 14 20:44:23 2012 -0400
summary:
IDLE was relying on implicit relative imports which have gone away in
Python 3.3 thanks to importlib finishing the work in PEP 328 that
accidently got carried forward.
I don't know if this patch will have any affect on this issue, but implicit relative imports are (were;-) a possible cause of intermittent problems.