cursor "jdbc_curs_1" does not exist

Hi!

org.postgresql.util.PSQLException: ERROR: cursor "jdbc_curs_1" does not exist

Can somebody explain this exception? What I do is pretty simple: I read text
from one table, gzip it and insert it into another table. But it seems that
the exception is thrown at ResulSet.next() but I'm not sure. Here's the code
anyway:

final PreparedStatement select = f4t.prepareStatement( "SELECT urlid, html
FROM html" );
final PreparedStatement insert = f4t.prepareStatement( "INSERT INTO
legacy.zhtml (id, zhtml) VALUES (?, ?)" );

f4t.setAutoCommit( false );

select.setFetchSize( FETCH_SIZE );

int i = 0;
for( ResultSet row = select.executeQuery(); row.next(); )
{
final String id = row.getString( "urlid" );
final String html = row.getString( "html" );

final ByteArrayOutputStream bos = new ByteArrayOutputStream();
final DataOutputStream dos = new DataOutputStream( bos );

WritableUtils.writeCompressedString( dos, html );

insert.setString( 1, id );
insert.setBytes( 2, bos.toByteArray() );
insert.execute();

System.out.print( '.' );

if( ++i % 100 == 0 )
{
System.out.println();
f4t.commit();
}
}

f4t.commit();
f4t.setAutoCommit( true );