ioctl(SIOCIPFL6): Invalid argument

Greetings all!

I am building a new FreeBSD box for a firewall.  The last one was running
3.4.31 so I guess it was time.  <grin>

I get this set of messages (new to me) when I am booting:

	Enabling ipfilter
	361:ioctl(add/insert rule):File exists
	423:ioctl(add/insert rule):File exists
	703:ioctl(add/insert rule):File exists
	1:ioctl(add/insert rule):File exists
	ioctl(SIOCIPFL6): Invalid argument
	Installing NAT rules.
	0 entries flushed from NAT table
	0 entries flushed from NAT list

I am concerned that lines 2 through 6 are errors, but my attention is
obviously drawn to the last one of the set of errors since it says "Invalid
argument".  I can't find this on the list and Google was not my friend, so I
thought I would ask you fine folks if my ship was sinking.

What exactly is ipfilter telling me, do I need to be worried and what can I
do to get a clean boot?

Thanks for your help!

--  Jeff