Use wheezy-backports suite from the Debian Mozilla team APT repo, not the squeeze-backports one
Originally created by @intrigeri on #7063 (Redmine)
The devel branch still has:
deb http://mozilla.debian.net/ squeeze-backports iceweasel-esr
We should use the wheezy-backports suite instead.
Feature Branch: bugfix/use-Wheezy-repo-for-debian-mozilla