ssh + su problem

[Will Parsons]

I have a problem in that I cannot su to root on a FreeBSD machine
remotely from a Windows machine.  Note that the user I'm logging in as
*is* a member of the wheel group (and I can su locally just fine).
Symptoms are:

% su
Password:
su: Sorry
%

Although I *think* the purpose of the sshd option "PermitRootLogin" is
to (dis)allow *direct* root ssh logins, I changed it to "yes" anyway
in sshd_config, but that doesn't seem to be the problem.

I'm inclined to think this a server-side configuration issue, since I
get the same result whether I use Cygwin ssh or PuTTY to log in
remotely to the FreeBSD machine.

Any ideas of what might be wrong?

-- 
Will