device em0 not showing up at boot

[Forrest Aldrich]

I have an older PC (Compaq AP200) that I'm running FreeBSD-6.0 on.

I have an Intel Gigabit interface installed in one of the PCI slots, 
along with another dual 10/100 Intel in another.

The "em0" device does not show up at boot time, and therefore the 
firewall rules fail.

However, if I go in and manually type "ifconfig em0" it then becomes 
available and I'm able to run dhclient on it, etc. etc.

I just did a buildworld/installworld today, so the OS is fairly current.

In /etc/rc.conf I have a simple ifconfig_em0="DHCP".

I wonder if this is a known problem...