Tracking down a problem in Django

This book has been written using the latest available Django release at the time of writing. Early on that was Django 1.1. Then, during the course of writing, Django 1.1.1 was released and everything written after that release date used Django 1.1.1. The three 1s in that release number are the major, minor, and micro release numbers. (A missing micro number, as in Django 1.1, is an implied 0.) Django 1.1.1, since it has an explicit micro number, is called a micro release. The only changes made in micro releases are bug fixes, thus micro releases are 100 percent backwards compatible with the previous release. While a change in a major or minor version number may involve some backwards-incompatible changes that require code adjustments, the only difference you will see in updating to a new micro release is fewer bugs. Therefore, it is always recommended to run the latest micro release for the major.minor version you are using.

Despite this advice and compatibility...