Some days ago, the new integration of Python-2.6.3 was announced, but contained an internal bug.
Python 2.6.4 is a critical bug fix for Python 2.6.3, which had regressions in the logging package and in setuptools compatibility. Python 2.6.4 was released on 25-Oct-2009 and is stable enough to be the new candidate for the new Py4D version.

Python 2.6 is now in bugfix-only mode; no new features are being added. The NEWS file lists every change in each alpha, beta, and release candidate of Python 2.6.