Query takes a long time

"select distinct t.bill_no, t.ref, t.bill_byr, c.name from artagih t, arcustomer c, arbill_lns where t.bill_no not in (select bill_no from arbill_lns) and t.cust_code=c.cust_code and t.d_r=arbill_lns.d_r and t.cust_code='CUST01' order by t.tanggal"

Is there something wrong with my query or do you have any suggestions?

If my query is correct, where is the problem? Is it in the postgre server or in ODBC?

Is there any OLE DB for Postgre, cause i'm using VB for my front-end application.

For comparison if i'm using MSDE for database server, it takes not more than 5 seconds for the same query with above.

With MySQL it takes over than 1 minute. I'm so confusing and stuck with this problem.

Thank you very much.

Roji