AndruC

To clarify, the post to be displayed requires both that its mpl_highlighted field has a value of 1, AND that the user’s location exists as a value of either country, state, or city.

The problem is that the second meta array’s value, location, could be associated with one of three different keys. Would that be written then, like this?

query_posts( array('post_type' => POST_TYPE,
  TAX_CAT => $term->slug,
  'ignore_sticky_posts' => 1,
  'posts_per_page' => 3,
  'meta_query' => array (
    'compare' => '=',
    'relation' => 'AND',
    array ( 'key' => 'mpl_highlighted',
	    'value' => 1),
    array ( 'compare' => 'how compare',
            'relation' => 'OR',
      array ( 'key' => 'country',
              'value' => $userlocation ),
      array ( 'key' => 'state',
              'value' => $userlocation ),
      array ( 'key' => 'state',
              'value' => $userlocation ) ),
    'orderby' => 'rand' ) );

I’ve noticed the problem, but I’ve only attempted it with a custom post type. Unfortunately, it’s going to be a major problem to fix manually.