No links being fetched by Net::Delicious

Hi,

I've been using a perl script with Net::Delicious to fetch my daily links every day for some
time and it's worked fine. Except now it fetches nothing. It worked when I del.icio.us'd
stuff was the March 12th, but the next time, on the 21st, it didn't.

Here's a test script:

--

#!/usr/bin/perl

use strict;
use Net::Delicious;
use Data::Dumper;

my $del = Net::Delicious->new({
    user   => 'philgyford',
    pswd   => 'mypassword'
});

my @links = $del->posts({
    tag => 'top',
    dt => '2008-03-21'
});

print Dumper (@links);

--

But that last line outputs nothing... Has something changed that I'm not aware of, or have
I made some dumb mistake?

Thanks,
Phil