If you began using WordPress prior to version 2.2, you may notice that your database has tables with two different character sets and collations. This is because all database tables created prior to WordPress 2.2 use the latin1 character set and the latin1_swedish_ci collation, and all database tables created after WordPress 2.2 use the utf8 character set and the utf8_general_ci collation.
(Via MacManX.com.)
James Huff has written a very handy how-to for fixing your WordPress character sets & collations. I highly recommend preforming the clean up if you’re technically savvy and have access to your MySQL database. I was in bad need of a clean up myself, and this helped tremendously. I was also able to fix some other lingering link and email address issues I’ve caused by serving my WordPress install on 3 different domains over the years.
Thanks for the mention, Jim! Call me old-fashioned (or not), but I’ve always felt that altering my database by editing a backup in a text editor was easier (and safer) than the direct command line method.
I’d have to agree with you there, James. Editing via SQL queries can be so time consuming for more than just a few changes, and one wrong query can ruin your whole day (or database).