Comment 11 for bug 776361

Do you have any rules in your iptables, try typing

sudo /sbin/iptables -L -n

Are there logging (LOG) rules displayed?

ls -l /var/log/messages

Does the file exist?
Is the timestamp recent?

If not then try a reboot and when your system returns, check the timestamp on the file and is it after your reboot, if it isn't then the change isn't active for some reason.