Error in pgsql

Hi
I converted the mysql database to pgsql for India. During report
generation using pgsql database I get the following error but in mysql
it runs fine. Can you please help me remove it.

"Exception (org.springframework.dao.DataIntegrityViolationException):
ERROR: duplicate key value violates unique constraint "period_pkey"
Detail: Key (periodid)=(85) already exists.; SQL [n/a]; constraint
[period_pkey]; nested exception is
org.hibernate.exception.ConstraintViolationException: ERROR: duplicate
key value violates unique constraint "period_pkey" Detail: Key
(periodid)=(85) already exists."