Are you able to reproduce this on 1.0.0rc2? Or on this installation?

on our development server we are having this error and it can be reproduce all the time

Had the same ... turns out that MySQL screwed up the sorting when doing a SELECT DISTINCT. Fixed it by replacing the distinct through a GROUP BY id in core/filter_api.php:

around line 724:

$query = "SELECT $t_bug_table.id AS id $t_from
$t_id_join
$t_id_where GROUP BY $t_bug_table.id";

around line 854:

$t_order = " GROUP BY id ORDER BY " . implode( ', ', $t_order_array );
$t_select = implode( ', ', array_unique( $t_select_clauses ) );

$query2 = "SELECT $t_select
$t_from
$t_join
$t_where
$t_order";

Hope that helps ... mysql version is 4.1.21-standard

It seems this is a duplicate of 0007476, and both not mantis fault: see comment 0007476:0013618.

Feel free to reopen if you believe that this is a different issue.