Literal vs parameterized 'timestamp with time zone' value

Hi there,

This one has been baffling me for several hours so I hope that the
list can help.

I'm having an awful difficulty specifying a parameter in a select
where clause of a prepared statement.

Please consider this schema:

Table "public.moving_object_status"
Column | Type | Modifiers
--------------+-----------------------------+-----------
validtime | timestamp(2) with time zone | not null
Indexes:
"moving_object_status_validtime" btree (validtime)

(other columns removed for brevity).

If I create the following prepared statement:

PreparedStatement sqlStatement =
sqlConnection.prepareStatement("select validtime from
moving_object_status where validtime < '2005-06-08T20:05:45.825+0'");

then 1 row is returned as I would expect given my dataset.

However if I use a parameter:

PreparedStatement sqlStatement =
sqlConnection.prepareStatement("select validtime from
moving_object_status where validtime < ?");
int columnIndex = 1;
sqlStatement.setString(columnIndex++, "2005-06-08T20:05:45.825+0");

No rows are returned.

Can anyone explain the difference in results given a literal value
and a parameterised value in this context?

Kind regards,
Christopher