Yes, this is getting really annoying. Somehow, there is always the one bug that manages to escape my grasp. This isn’t my fault, or for anyone’s for all I know. It just happened.
Sorry for those affected (German users), one of the language files was improperly encoded as a Windows encoding (should have been UTF-8). Hopefully you aren’t completely mad, I’m not exactly sure at what point the file changed encoding, it just did.
So 3.2.1.3.1 (what an ugly version number) has been uploaded to AMO and contains the proper locale. Sorry for any inconvenience.