InputStream as parameter not supported

I am using PostgreSQL 7.0, with the jdbc7.0-1.2.jar file.
I am trying to send a Large Object to the database but get an error saying
'InputStream as parameter not supported'
The offending statement is
'stmt.setBinaryStream(1, geomStream, geomStream.available());'
where geomStream is an instanceof ByteArrayInputStream and stmt is a
PreparedStatement.
The exact same code runs beautifully under Oracle, but throws this exeption
under PostgreSQL.
I have followed the documentation to the letter so I don't see why it throws
the exception.
The field in the table is of type 'oid', which the documentation uses.