ERROR: column "total_cost" is of type numeric but expression is of type character varying

Hi,
    I am testing PostgreSQL 8.0.1. I compiled and installed it.
Downloaded JDBC driver postgresql-8.0-310.jdbc3.jar for JDK 1.4.(I was
unable to find it in source) Dumped my 7.3.3 database. Restored it in
new installation. Run the application and it gives this error.
    The error is when I use setString() to insert into a numeric
field. I hope it is bug. Otherwise we have to rewrite our application.
    The error message can be seen in server log also.

rgds
Antony Paul