Gentoo recently switched to make python 2.6 the default python. This means that mod_python and mod_wsgi will be re-compiled against 2.6. Which means that any python modules you’re using with Apache will also need to be re-compiled against the new version or you’ll get version mis-match errors. If you’d rather not go through all that work you can tell portage not to upgrade with the following line in /etc/portage/package.mask:

Note to self: on Gentoo postgresql configuration files (pg_hba.conf and postgresql.conf found in /var/lib/postgresql/data) need to be owned by the postgres user. So if you edit them as root, reset the owner:group before restarting postgresql.