Cron Jobs Not Running

I have a machine, that for some reason stopped running it's cron jobs for some reason, and I can figure out how to get them working again.

My /etc/crontab file is as follows.

SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/

# run-parts
01 * * * * root run-parts /etc/cron.hourly
02 4 * * * root run-parts /etc/cron.daily
22 4 * * 0 root run-parts /etc/cron.weekly
42 4 1 * * root run-parts /etc/cron.monthly
Here are the contents of a sample user cron file.

MAILTO="USER"
10 4 * * * php -q -f /home/USER/public_html/tools/updtransfers.php /home/USER/public_html >/dev/null 2>&1
10 5 * * * php -q -f /home/USER/public_html/tools/updateexp.php /home/USER/public_html >/dev/null 2>&1
10 5 * * * php -q -f /home/USER/public_html/tools/invoice_cron.php /home/USER/public_html >/dev/null 2>&1
and another

*/5 * * * * /usr/local/bin/php -c /home/USER/php.ini /home/USER/public_html/poller.php > /dev/null 2>&1
I've checked my logs, and I can find no errors anywhere. When I run the commands manually via SSH, they work perfectly, they simply are not being run automatically the way they are supposed to be.

I have checked, and the crond service is running. I have tried restarting it, but it seams to have no affect. I really have no idea what the issue is. The only thing I seam to have found at one point, was the possibility that the files within the /etc/cron.d directory might be CHMOD'ed wrong, but I haven't found anything to confirm this either way.

[root@server cron.d]# ls -all
total 60
drwxr-xr-x 2 root root 4096 Dec 17 03:07 .
drwx--x--x 94 root root 12288 Jan 3 09:28 ..
-rw-r--r-- 1 root root 61 Jun 22 2007 csf_update
-rw-r--r-- 1 root root 81 Apr 11 2007 lsm
-rw-r--r-- 1 root root 79 Jun 22 2007 prm
-rw------- 1 root root 366 Feb 23 2007 sa-update
-rw-r--r-- 1 root root 82 Jun 22 2007 spri
-rw-r--r-- 1 root root 188 Nov 16 23:14 sysstat
[root@server cron.d]#