...fails with the error: "error calling method of a PBNI". I have been
unable to create an instance to, for example, a java.sql.Timestamp. I am
quite sure java.math.BigDecimal and other java classes will also be
affected by this.

My workaround: Create user defined extender types on java side, with
empty constructors, and a getter method returning the original type.

Thanks,
Gokhan