existing sendmail aliases ignored until sendmail restart

On this system, /etc/mail/aliases has an entry to send root email to 
another user on another computer.  newaliases was last run on October 
14:

-rw-r--r--  1 root  wheel   1693 Oct 14 07:18 aliases
-rw-r-----  1 root  wheel  16384 Oct 14 07:18 aliases.db

After booting 8.0-RC1, the root alias in the already-built alias files 
is ignored by sendmail.  The mail is sent to the un-aliased root.

The existing .mc file does take effect (in this case, mail is still sent 
to a smarthost, where it bounces, since root_at_lightning.wonkity.com 
doesn't exist there).

A 'make restart' of sendmail--without touching anything else--and the 
alias works.

FreeBSD lightning 8.0-RC1 FreeBSD 8.0-RC1 #11: Thu Oct 22 13:03:43 MDT 
2009     root_at_lightning:/usr/obj/usr/src/sys/LIGHTNING  i386

This has been going on for a while; at least the last half-dozen 
rebuilds of 8.0-RC1 on this system have exhibited the problem.  It's a 
regression from 7-STABLE.

To recreate:

Enter an alias in /etc/aliases (only root tested).
newaliases
Reboot.
Send mail to that alias (failure).
cd /etc/mail; make restart
Send mail to that alias (success).

-Warren Block * Rapid City, South Dakota USA