setObject() throw exception message: "The table for java.util.Date is not in the database. ..."

Hi,  did someone on the net hit such exception? 

1. The exception stack:

The table for java.util.Date is not in the database. Contact the DBA, as the database is in an inconsistent state.
    at org.postgresql.jdbc1.AbstractJdbc1Connection.storeObject(AbstractJdbc1Connection.java:753)
    at org.postgresql.jdbc1.AbstractJdbc1Statement.setObject(AbstractJdbc1Statement.java:1470)
    at org.jboss.resource.adapter.jdbc.local.LocalPreparedStatement.setObject(LocalPreparedStatement.java:625)
    ....<snip/>

2. The java program snip:

String script = "SELECT MAX(\"id\") FROM \"vEntry\" WHERE \"when\" BETWEEN ? AND ?";
PreparedStatement stmt = conn.prepareStatement(script,
        ResultSet.TYPE_FORWARD_ONLY,
        ResultSet.CONCUR_READ_ONLY);
stmt.setObject(1, beginDate); //<------------ exception occured at this line
stmt.setObject(2, endDate);

3. I have tried rewrite the sql script to
    SELECT MAX("id") FROM "vEntry" WHERE "when" >= ? AND "when" <= ?

and it works without problem.

4. Oh, and vEntry is a VIEW.

5. Environment
Win2k, service pack 3
cygwin.dll version: 1.3.17
postgresql  7.3-1
postgresql.jar 2003/3/23
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1_02-b06)

Can some gurus out there help me on this?

Henri Chen