If DST isn't used in your area, just shut it off. The time stamp relies on the server's local time and, although this is very rare, it does sometimes slip. If there's a substantial difference between your time and the stamps, this would point to a change needed here: http://preggophilia.com/usercp.php?action=options
Again, daylight savings is almost always the culprit. Let me know if this fixes it.