BUG #5646: missing chunk number 0 for toast

The following bug has been logged online:

Bug reference:      5646
Logged by:          missing chunk number
Email address:      chand.vizag@gmail.com
PostgreSQL version: 8.3
Operating system:   Linux
Description:        missing chunk number 0 for toast
Details:

Hi,
when i run my table in editor i faced this below error.
Ex: select * from ad_role

ERROR:  missing chunk number 0 for toast value 525559 in pg_toast_325765

********** Error **********

ERROR: missing chunk number 0 for toast value 525559 in pg_toast_325765
SQL state: XX000


How can i solve this error.Can u guide me.

with regards,
chandrasekhar