Postgres 6.3 still has problem with the index

We were under the impression that the 6.3 resolved the index corruption
issue with regard to large tables(BTP_CHAIN). The problem still exist
and our table indices are still corrupting every night.  We are very
desperate and need your help to resolve this issue. Our database size is
about 80M and growing. We have one particular table (User_Account) about
12M, that is heavily accessed and updated. Almost every time the number
of simultaneous access increases, the index on this table corrupts. What
type of information can I present to you to help resolve this issue.

Sincerely

Ali Ebrahimi
Atlas Field Support Manager