Turns out I was importing it into the wrong database!
There’s one database named _wor1 whose table names all begin with dcm_, and another named _wrd1 whose table names all begin with wp_. Naturally I assumed this was the correct one.
My hosting control panel shows the initial installation of WP as well as the current one. I guess when I updated the version it left the old one intact. Did they change the default database table names between version 3.3.x and 3.5.x?
Anyway, all is well in my world now, and no clenching has been required.
Alan