"incompatible character encodings: ASCII-8BIT and UTF-8"

Hi!

Just started to learn Rails, and I get this error when i'm trying to
make a simple forum-app (much like the screencast about making a blog in
15min at rubyonrails.org). This appears when I try to render a partial -
that is posting a comment containing swedish letters å (å), ä
(ä) and ö (ö).

I can view those posts by going to localhost:3000/posts/ using the
scaffold generated new, edit and show. This error only appears when
rendering a partial.

I've tried to change encoding to UTF-8 everywhere I could find, tried
with latin1 aswell. Can't figure out what's wrong. I've googled,
searched a number of forums....

Thankful for any help!

Regards /Björn