eg on http://moodle.org/tag/index.php?tag=guinness

Did you remember to make the first column something unique in your call to get_records? Duplicate value '1' found in column 'id'.

• line 741 of /lib/dml/mysqli_native_moodle_database.php: call to debugging()
• line 949 of /tag/lib.php: call to mysqli_native_moodle_database->get_records_sql()
• line 458 of /tag/lib.php: call to tag_get_correlated()
• line 106 of /tag/locallib.php: call to tag_get_related_tags()
• line 93 of /tag/index.php: call to tag_print_description_box()

Here is the line:

if ( !$result = $DB->get_records_sql("SELECT tg.id, tg.tagtype, tg.name, tg.rawname, tg.flag, ti.ordering
FROM

tg INNER JOIN

ti ON tg.id = ti.tagid
WHERE tg.id IN ({$tag_correlation->correlatedtags})") ) {

Is it because of the join? I think the DB is ok.