We need to tag following builds as override:
nss-softokn-3.13.1-14.fc16
nss-softokn-3.13.1-14.fc15
nss-util-3.13.1-3.fc15
nss-util-3.13.1-3.fc16
nss-3.13.1-9.fc16
nss-3.13.1-9.fc15
xulrunner-9.0-2.fc16
xulrunner-9.0-2.fc15
nspr-4.8.9-2.fc15

This is due to fixing langpacks issue with latest firefox and thunderbird security update, see:
https://admin.fedoraproject.org/updates/nss-softokn-3.13.1-14.fc16,nss-util-3.13.1-3.fc16,nss-3.13.1-9.fc16,thunderbird-lightning-1.1-0.1.rc1.fc16,thunderbird-9.0-2.fc16,firefox-9.0-2.fc16,xulrunner-9.0-2.fc16

https://admin.fedoraproject.org/updates/nspr-4.8.9-2.fc15,nss-softokn-3.13.1-14.fc15,nss-util-3.13.1-3.fc15,nss-3.13.1-9.fc15,thunderbird-lightning-1.1-0.1.rc1.fc15,thunderbird-9.0-2.fc15,gnome-python2-extras-2.25.3-35.fc15.3,perl-Gtk2-MozEmbed-0.09-1.fc15.7,firefox-9.0-2.fc15,xulrunner-9.0-2.fc15

I can't do it by Build override tag request because the form says it has been already overridden.

Thanks a lot for your help.