Problem adding keywords - Invalid keyword text!?

[Zelig]

Hello there...

I'm using the AdGroup API to add keywords to an AdGroup - My problem is
keywords that contain special characters like e.g. æøåäü. While
the setup I'm using can add these characters without problems to
campaign names, adgroup names etc. - It fails to do so for keywords
(keyword.text) reporting invalid keyword text.
I've tried all to change encoding in different ways but the results are
the same.

What is wrong here?

[AdWordsAPIAdvisor]

Valid keywords are <= 80 characters, <= 10 words, and composed of
letters, numbers, and friends (' ', '#', '$', '&', '_', '-', '\"', '[',
']', '\'', '+', '.', '/', ':', and '\u3000').

Non-ASCII characters should show up as references in your XML. E.g.:

<text>&#xE6;&#xF8;&#xE5;&#xE4;&#xFC;</text>

-- Brian Kennish, Google