Posting to newsgroups with non-ASCII encoded names?

[Jacob Sparre Andersen]

Gnus doesn't have problems with reading articles posted to newsgroups
with non-ASCII encoded (UTF-8 and ISO-8859-1) names, but it will not
(with my configuration) let me post articles to the same groups.  The
error message I get is »Couldn't send message via news: 441 No valid
newsgroups in "dk.test.utf8-æøå"«.  It works fine, if I use the
`rpost` command (from "suck") to post to the same groups, and one of
my friends can also post with `slrn` without any problems.

Can I do something to my configuration of Gnus, which will fix this
problem?

Jacob
-- 
"Hungh. You see! More bear. Yellow snow is always dead give-away."