just grasping in the dark, but it does seem that some of those unicode ''packs'' aren't loaded, to say the least. this is only a guess by someone who doesn't know a lot of this.
tried resetting firefox btw? it does reset other things like addons and preferences I think, but it can fix it.
I think it was help>troubleshoot information, or type in the adress bar
''about:support''
without the ''
at the top of this page you'll find a button with ''reset firefox''
however, only use when all else fails I think, because it may be a pain to get everything like you want.