Weird datetime problem

I have 2 tables both of which have a datetime field and both have an
identifier of date_submitted.

I've been using(via PHP) a query of the following for a month or so with
no problem:

select count(*) from mytable1 where date_submitted > 'today'::datetime

and

select count(*) from mytable2 where date_submitted > 'today'::datetime

Both queries were working fine until I dumped the data in mytable2 to
file and reloaded it. Now I can enter a date and not get the rows that I
put in today(or any other day).

The date_submitted has a btree index on it. I've even dropped and created
a new index and that still hasn't helped. I still come up with 0 rows
found.

All I'm trying to do is get the number of rows submitted since midnight.

Oh, yeah, Postgres 6.4.2, PHP 3.0.7, Linux Slackware 2.0.35, Dual Pent
450's.

Anyone have any ideas?

Thanks in advance.

Andy