I did both of those things and I'm still not able to reproduce it. Do you have any specific language settings enabled? 

One thing I meant to ask in my last message was if you had a copy of what you tried to paste into the window. I've pasted a 500 character string of "a" repeated, and 500 of "ñ" in case this was a Unicode issue. Neither caused a problem.

As for a debug build, we don't provide one anywhere. If you are interested in creating a debug build, http://www.python.org/dev/faq/ has instructions for downloading the source so you could make your own.