Custom taxonomy encoding issue

I’ve created a custom post type (cpt) and two custom taxonomies (ctB) and (ctC).

Now I’m trying to set up the following templates:
taxonomy-ctB.php
taxonomy-ctC.php

The templates works fine as long as the taxonomy name doesn’t contain “?, ?, ?”. If they do – no posts shows up. If I replace “?, ?, ?” with “a, a, o” the listing of posts works fine, but the page looks like crap since the name isn’t correct Swedish.

So say that…
cpt = Product
ctB = Brand

…and then I create two products one called ?rjan another called Stig, I put the first in the brand ?bergs and the second in Ericsson. The result would be:
– ?rjan product page works fine.
– Stig product page works fine.
– ?bergs taxonomy page looks good apart from the fact that it can’t pull up the products for this brand.
– Ericsson taxonomy page works fine.

… If I now change ‘?bergs’ to ‘Abergs’ that taxonomy page works as well.

Without having a clue what to do to fix this…

I’ve changed DB_COLLATE to utf8_swedish_ci in wp-config.php.

In the database I’ve also changed the collation for:
– wp_term_taxonomy
– wp_terms

Not sure if it would help to change this too ‘wp_term_relationships’.

I’ve spent most of the day looking for similar issues and solutions but I haven’t found anything.