Crontab running twice, making duplicates

I am new to dreamhost and I am transferring my site over from an old host. Anyways .......

I setup my new crontab in SSH. It works OK, but it's sending duplicate emails, which means it's running twice each time it's supposed to run once.

This is a PHP script that emails out digests from a phpbb forum. This cron worked just fine on the old host and only sent 1 email per run.

Here's my crontab -e:
MAILTO="me@somewhere.com"
# minute (0-59),
# | hour (0-23),
# | | day of the month (1-31),
# | | | month of the year (1-12),
# | | | | day of the week (0-6 with 0=Sunday).
# | | | | | commands
30 * * * * GET http://name:pass@www.vcomstudent.com/forum/cron/mail_digests.php >/dev/null

It looks ok to me. Any ideas why it's running twice each time?

Thanx
Snuffy2