Movable Type To WordPress Permalink Oddness

For some bizarre reason the WordPress importer changes the post names from “thing-other-thing” to “thing_other_thing” ie. replacing the dash with an underscore.

The simplest way to fix it is to run a bit of SQL directly on the database:

update wp_posts set post_name = replace(post_name,’_’,’-‘);

Thanks to the person who provided the solution here