INTERVAL parameter in PreparedStatement worked in 7.4 but not in 8.0 driver

Hello,

I used to use the following style statement with the 7.4 series JDBC driver:

select * from users users where users.createdDate < (CURRENT_DATE -
INTERVAL ?)

and would set the parameter to a string value of "14 DAYS"

but in the Postgres 8 driver, this query executes but does not seem to
ever return anything. Is there a better syntax I could use to make this
work?

The query does work in the 8 driver if the ? is explicitly part of the
query, i.e. not a positional parameter, like this:

select * from users users where users.createdDate < (CURRENT_DATE -
INTERVAL '14 DAYS')

Any help much appreciated,
m@