Comment 16 for bug 348704

I suspect this is because of bug #353251. python2.6-minimal is unpacked and setup in line 875pp of the upgrade log. At this time the python-minimal version that contains the file /usr/share/python/debian_defaults is still the intrepid version (that package gets upgraded in line 1164). The debian_defaults file does not contain python2.6 yet (because its still the intrepid version). The postinst of python2.6-minimal reads this file and only runs the "rtinstall" scripts if python2.6 is marked as supported in debian_defaults.

This would also explain why some people see the problem and some not. It depends on the unpack/configure ordinging. If python-qt4-dbus is unpacked/configured before python2.6-minmal is unpacked the link is not created because the global rtinstall for python2.6 of pysupport (and pycentral) is not run.