Invalid charcters handling

hi ,
I am facing this below issue can u suggest me a solution to retcify
this probleem at earliest.

Exception [TOPLINK-4002] (Oracle TopLink Essentials - 2.0.1 (Build b04-fcs
(04/11/2008))): oracle.toplink.essentials.exceptions.DatabaseException
Internal Exception: org.postgresql.util.PSQLException: Invalid character
data was found. This is most likely caused by stored data containing
characters that are invalid for the character set the database was created
in. The most common example of this is storing 8bit data in a SQL_ASCII
database.
Error Code: 0

Kamaraju Prathi
Tata Consultancy Services
Mailto: kamaraju(dot)prathi(at)tcs(dot)com
Website: http://www.tcs.com
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