@Quan Da Yong: sorry for the delay getting back to you on this... the OSIsoft vCampus program/community is focused around PI programming and intregration questions (e.g. manipulating PI Notifications programmatically, using PI Web Services, etc.)
This is purely a PI System administration/configuration question, and our regular Technical Support team is much better staffed/equipped for this kind of questions. From your original post it seems like you already dealt with tech support on this issue... I would strongly recommend you follow-up with them to work on this issue.
Looking forward to answering your programming/integration questions!