I had the same error as Paul Menzel preventing Iceweasel startup, purging the incompatible language package solves it. Look for an old (ie. 7.0.1) iceweasel-l10n package.
Hope it helps. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org