Some Python teacher in the Philippines was having trouble with Python 3.1 and IDLE. Too much crashing. I've heard of that problem before, especially from OSX users.
Eclipse is a big and complicated program, but maybe it's still OK for classroom use, running Pydev? Depicted above, a Python 2.6 project running on Windows 7.
On the other hand, some of the advice might have solved IDLE problems. Even on Eclipse, if you're preventing the internal loopback, you're going to have problems booting a console, am I right?
A reading for my Pythonic geometry students: Polyhedral Numbers by H.S.M. Coxeter.