Language mixup

Hi!

I tried some plugins that allowed for different front and back end language but had to quit that.

Now I try to have only 1 language (da_DK).

Wp-config is set to: $locale=’da_DK’;
Database wp_options is set to WPLANG = da_DK

But the wordpress setting cannot be changed from the “English (US)” by saving in other language, even though backend clearly is in danish.

My problem is that certain other plugins apparently get confused and I end up with mix of english and danish.

So the question is, how do I force wordpress to report and respect da_DK, given the things I already did ?

Cheers