[Tutor] Strange issue w/ Python shell 3.0.0.

[Rafael Knuth]

> Oh, wait, I see you are using Python 3.0. Don't. Python 3.0 is not
> supported because it is buggy. You should use 3.1, or better still, 3.3.
> Python 3.3 is much better than 3.1 or 3.2, and 3.0 is buggy and slow.

What I was trying to say is that sometimes I get runtime errors even
if nothing's wrong with my code.
I had those issues with Python 3.3.0 ... I wrote a program and when I
executed it, and a runtime error occured.
I then copy and pasted that into a new window, I saved it and -
surprise, surprise - it ran without any issues. Although I didn't
modify my program in any ways.
That's why I came up with that question that might sound odd to you
whether Python shell somehow "caches" older, buggy versions of my
program which I saved previously  ...