JDBC + large objects problem

I'm trying to use JDBC and BLOBS to store large amounts of text in a
database. I get a strange error when I try to use the conventional JDBC
interface... it comes out with a SQL Exceptions of:

"InputStream as parameter not supported"

for the code:

Connection conn = pool.getConnection();
PreparedStatement pstmt =
conn.prepareStatement("INSERT INTO t" + book
+ "_data (author_id, title, text,
type) VALUES ( ?, ?, ?, ?)");
pstmt.setInt(1, userId);
pstmt.setString(2, title);
InputStream textStream = stringToStream(text);
pstmt.setBinaryStream(3, textStream, text.length());
pstmt.setInt(4, type);
pstmt.executeUpdate();
pstmt.close();

... with some helper functions....

private InputStream stringToStream(String string) {
byte[] bytes = string.getBytes();
ByteArrayInputStream stream = new ByteArrayInputStream(bytes);
return (InputStream) stream;
}

private String streamToString(InputStream stream) {
try {
int length = stream.available();
byte[] bytes = new byte[length];
stream.read(bytes);
return new String(bytes);
} catch (IOException e) {
System.out.println("No Stream");
}
return null;
}

with an abbreviated schema of....

>> \d t1_data
Table "t1_data"
Attribute | Type | Modifier
-----------+---------+-------------------------------------------------------
data_id | integer | not null default
nextval('t1_data_data_id_seq'::text)
author_id | integer |
title | text |
text | oid |
type | integer |
time | time |
Index: t1_data_pkey

.... using postgresql 7.0 and the newest JDBC driver from retep.org.uk

if ya'll have any ideas why it does what it does, i just might kiss your
feet. =)

-Patrick.