Comment 3 for bug 446004

And so how do i fix my system:

Setting up python3.1-minimal (3.1.1-0ubuntu5) ...
mkdir: cannot create directory `/usr/local/lib/python3.1': Permission denied
dpkg: error processing python3.1-minimal (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of python3.1:
 python3.1 depends on python3.1-minimal (= 3.1.1-0ubuntu5); however:
  Package python3.1-minimal is not configured yet.
dpkg: error processing python3.1 (--configure):
 dependency problems - leaving unconfigured

The bottom line is that /usr/local is defined by FHS as being site-local and anyone/anything other than the sysadmin should not be expecting to be able to do anything in there as it is by definition for the local administrator and packages should not be meddling in.