Index: wp-includes/taxonomy.php
===================================================================
--- wp-includes/taxonomy.php	(revision 5769)
+++ wp-includes/taxonomy.php	(working copy)
@@ -791,12 +791,14 @@
 	$terms = array_map('intval', $terms);
 
 	$taxonomy = get_taxonomy($taxonomy);
-	if ( isset($taxonomy->update_count_callback) )
+	if ( ( isset($taxonomy->update_count_callback) ) && ( '' != $taxonomy->update_count_callback ) )
 		return call_user_func($taxonomy->update_count_callback, $terms);
 
 	// Default count updater
-	$count = $wpdb->get_var("SELECT COUNT(*) FROM $wpdb->term_relationships WHERE term_taxonomy_id = '$term'");
-	$wpdb->query("UPDATE $wpdb->term_taxonomy SET count = '$count' WHERE term_taxonomy_id = '$term'");
+	foreach ($terms as $term) {
+		$count = $wpdb->get_var("SELECT COUNT(*) FROM $wpdb->term_relationships WHERE term_taxonomy_id = '$term'");
+		$wpdb->query("UPDATE $wpdb->term_taxonomy SET count = '$count' WHERE term_taxonomy_id = '$term'");
+	}
 
 	return true;
 }