problem spawning a call to the WP-Cron system

I have a site where I am importing Facebook posts using the Facebook Fanpage Plugin and the DsgnWorks Instagram Imported to WordPress. I have been experiencing issues with the imports running automatically and since then have installed WP Crontrol and Core Control to try to debug it.

On the WP Crontrol interface I get the following error message:

There was a problem spawning a call to the WP-Cron system on your site. This means WP-Cron events on your site may not work. The problem was:
Unexpected HTTP response code: 404

I have tried a few solutions with no luck so far.

Deactivating all my plugins besides the importers and WP Crontrol – still get the same error message.

Enabling ALTERNATE_WP_CRON in wp-config.php – this removed the error but none of the crons were running.

Manually setting up the cron job on the server (Plesk 12.0) – this is the code I added as a scheduled task:

*/5 * * * * wget -q -O – http://blog.city-models.com/wp-cron.php?doing_wp_cron >/dev/null 2>&1

It did nothing.

I changed a few settings on the server including allow_url_fopen – this allowed the Instagram imports, but only manually – the error message was still there.

I read on one of the many forums about the server possibly blocking loopback requests – I am not sure what this is and how to unblock it – if this is the problem does anyone know how to unblock loopback requests on a server?

Here is the url to the blog http://blog.city-models.com/ – I am using the Being Hueman theme, child of the Hueman theme.