strange lease with isc-dhcp3-client

[Hanspeter Roth]

Hello,

since I upgraded to 6.0-Release the dhclient.conf doesn't work
anymore. So I installed the isc-dhcp3-client and set
/etc/rc.conf:dhclient_program to /usr/local/sbin/dhclient.

When the program executes at boot it gets an address 0.0.0.0. When
it is stopped and restarted it gets a normal address.
What's wrong? How can I get a normal address at boot time?

-Hanspeter