kanden

Actually

I think the issue is in the section:

$excluded_categories = array_map('intval', explode(' and ', $excluded_categories));
if ( !empty($cat_array) ) {
$excluded_categories = array_diff($excluded_categories, $cat_array);
$posts_in_ex_cats_sql = '';
}

When I use the parameter like this 1,2,3 and by pass the above section, everything works fine IN or NOT IN

Again, Just my thoughts, not a solution for production.

Disclaimer(s)
1. I know this is bad form
2. This issue might be resolved in another forum
3. This is not a solution just a thought

I’m using 2.7 and I changed line #887 of link-template.php

TO:
$posts_in_ex_cats_sql = ” AND tt.taxonomy = ‘category’ AND tt.term_id IN (” . implode($excluded_categories, ‘,’) . ‘)’;

FROM:
$posts_in_ex_cats_sql = ” AND tt.taxonomy = ‘category’ AND tt.term_id NOT IN (” . implode($excluded_categories, ‘,’) . ‘)’;

It now works as a include cats parameter.