My dictionary works just fine as it is on my Kindle 3. If it doesn't wok on your Kindle, chances are that the books that you tried it with, weren't encoded as Swedish languages books or that your Kindle firmware doesn't support languages other than the usual EFIGS languages.
Trying to change the dictionary language with Calibre is pointless because Calibre
cannot change the dictionary input language.
You may want to use
Java Mobi Metadata Editor instead to make sure that your books are properly encoded.