Perhaps MySQL is defaulting to Latin1?
It supports Unicode, but it isn't quite as easy as one might hope.
I found this to be helpful:
Eric W. Brown
[mailto:email@example.com] On Behalf Of James M Safley
Sent: Tuesday, September 15, 2009 1:07 PM
To: MediaWiki API announcements & discussion
Subject: Re: [Mediawiki-api] Problem with special characters upon edit.
What encoding did you set up for the wiki?
The database character set is MySQL 4.1/5.0 binary.
The 'Æ' character should be encoded in UTF-8
as %C3%86, %C6 is in
Then it seems that Zend Framework's HTTP client library or PHP's
http_build_query() function is incorrectly encoding the string, since the 'Æ'
I'm passing is indeed UTF-8.
It is apparent that this is NOT a MediaWiki API bug, but any further suggestions are
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