I raised the issue described in Make a note: how an XBee replies to 'IS' command post on the package author's development group here. Paul replied, that the issue has been fixed for a while in the latest source code.
If you face the same issue (get 0x97 packet insted of 0x92 and the package fails to parse samples), here's what Paul advises:
As it happens, this bug has already been reported and fixed; a much more recent codebase which includes this fix is available at our Google Code source control: http://code.google.com/p/
python-xbee/source/browse/. If you click the 'Download zip' link, in the approximate middle of the navigation bar, you will get the very latest version of the code.
I have not gotten around to updating the python-xbee distribution and documentation in quite some time; I apologize for this.