Updating to a modular kernel

[Chris Ross <cross+netbsd%distal.com@localhost>]

  I'm not certain that modules are the crux of the issue, or even for  
sure that the -current GENERIC needs them.  But...

  I have a machine that has been running netbsd-5  
(NetBSD_5.0_STABLE).  I'm trying to update back into -current for the  
first time in more than a year.  I knew to unpack the modules set and  
install new bootstrap before rebooting the new kernel, and then I  
installed the rest of the sets (built from today's sources,  Or maybe  
yesterday's).

  Most everything is working, except my mfs /tmp.  At boot, I see:

Mounting all filesystems...
mount_mfs: /tmp: mount: Unknown error: 252
/etc/rc.d/mountall reported failure status 1

  So, I though maybe I needed to load the module.  I put a "load=mfs"  
on my boot.cfg, and did see on the next boot:

8987084+493396+539816 [476512+461973]=0xa75ad8
Loading /stand/i386/5.99.24/modules/mfs/mfs.kmod
Loading /stand/i386/5.99.24/modules/ffs/ffs.kmod
Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,  
2005,
    2006, 2007, 2008, 2009, 2010
    The NetBSD Foundation, Inc.  All rights reserved.

  However, the same error occurs trying to mount /tmp.  The relevant  
line in my fstab was/is:

/dev/ld0b /tmp mfs rw,-s=1052352

  Anyone know what important detail of change I missed?  Thanks...

                      - Chris