arp/dhcp question

[JD Bronson]

I recently moved my PPPoE onto my 4100 modem.

Tt is capable of passing my public IP into the freebsd box
and then when I reboot, since the modem keeps my connection alive I 
dont change IPs as often...This works very well...but, however, this 
has caused a new twist:

My modem appears to be at IP 192.168.0.1

My freebsd box has 2 NICs in it:

WAN = DHCP (connected to the 4100 modem)
LAN = 10.0.0.1

When the freebsd box boots, it asks for a DHCP address and the modem 
hands it a public one...207.227.122.7 for example.

This works well...with one exception:

Each so many seconds or so, my dmesg is filled with tons of these:

arplookup: unable to enter address for 192.168.0.1
arplookup: unable to enter address for 192.168.0.1
arplookup: unable to enter address for 192.168.0.1
arplookup: unable to enter address for 192.168.0.1
arplookup: unable to enter address for 192.168.0.1
arplookup: unable to enter address for 192.168.0.1
arplookup: unable to enter address for 192.168.0.1
arplookup: unable to enter address for 192.168.0.1

Now I certainly know why, but cant seem to solve this.
If I try to add an alias IP on the WAN NIC (after DHCP) this works 
but seems to kill off dhclient so once it gets a public IP it never 
asks/updates again.

I am looking for a solution either in a NIC or route command...

I could tell the modem to hand me a private IP but I would prefer to 
have the freebsd box use a public.

Help?

-JD