Problemns after updating from 6.1.4 to 6.1.5

[Paul Goyette <pgoyette%mail.netbsd.org@localhost>]

It seemed like such a simple thing.  Just boot up a new 6.1.5 kernel, 
extract the new distribution sets, run etcupdate and postinstall, and 
should be done, right?

Wrong!

I've got two problems at the moment.  First is su(1) doesn't work:

I _know_ I'm using the correct root password, but still I get

        su: Sorry: authentication error

And, in /var/log/authlog I get

        su: BAD SU paul to root on /dev/pts/1: authentication error


FWIW, when I ran postinstall, it told me to "fix" the old ptyfs
devnodes, so I did.  Is this the source of the problem?  And if so,
what's needed to get my su back?

My second problem is a bit more concerning.  I can no longer send any 
mail!  Receiving mail is fine, but when sending mail I get the following 
in my /var/log/maillog file:

	postfix/postdrop[4338]: warning: mail_queue_enter: create file
	maildrop/102777.4338: Permission denied

It's not at all clear to me where maildrop directory is.  And it is also 
not clear to me why this is broken, since I took great pains to avoid 
modifying the postfix {master,main}.cf files during etcupdate.

Any clues will be greatly appreciated.