We need more information to be able to assist you:

1. How do you launch IDLE?  Are you clicking on an icon and, if so, which one, or are you entering a command from a terminal window or something else?

2. When IDLE starts up, what are the exact lines that appear first in the Python Shell window it opens?  It should be something similar to but not identical to:

Python 3.2.1rc1+ (default, Jul  3 2011, 23:55:09) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>>

3. What is the contents of the script that causes the crash?

4. What are the exact commands you enter to produce the crash?

5. If you aren't already, try launching IDLE from a Terminal.app shell window this way, assuming you used a python.org installer:

   /usr/local/bin/idle3.2

If IDLE crashes, what is reported in the terminal shell window?

Thanks!