can't login as anyone - not even as root!

[Charles Howse]

> > >I didn't forget my password. I simply can't login. No one 
> can login.
> > >Even when my root password is set to nil I can't login.
> > 
> > Not even in single user mode?  There is no login in single 
> user mode,
> > you are root by default with no password.
> 
> Yes, I get the root # prompt, but I can't use the command passwd.
> It just prompts me for a password even  though the password is null.
> I used vipw so the master.passwd file is updated.

That doesn't sound right, in single user mode the prompt is 'ok'.
Are you mounting your filesystems?