set parameter not enabled?

I got the following from a jdbc call:
Exception: Callable Statements are not supported at this time.

this exception comes out from a third party pure java report engine, thus
the detailed information is not very much clear to me. When I was using
Oracle as database backend, this exception is not there. however, when I
change to postgres's  pgjdbc2.jar  JDBC driver, this exception raises. Does
that mean Postgres doesn't support stored procesure?

thanks a lot!