dhcp only works once on wifi card

Hi,

Have a wifi card that dhcp's fine on startup, however, every time the
AP drops off (say 15-45min), it loses it's ip adress, and never asks
for a new one.  Adapter has "blah blah blah DCHP" in it's ifconfig
entry in rc.conf, what am I missing?  Do I need to place
dhclient_enable="YES" in rc.conf or something like that?  The man page
for dhclient seems to assume it's always run from the command line,
afaik, although the -b switch would indicate otherwise...

Thanks,
Steve

-- 
Steve Franks, KE7BTE
Staff Engineer
La Palma Devices, LLC
http://www.lapalmadevices.com
(520) 312-0089