I did Archive & Install with "preserve users", why do I now have NO users?

Question

After a hard crash on my mom's PowerBook G4 (running 10.4.11) I eventually did an OS 10.4 Archive & Install with "preserve users". I now have NO users, not even an administrator, what should I do?  The only indication I see that anything was remembered is the login screen does say:
Mac OS X
Jane Brown's Computer
(But as I recall, there's a bug that sometimes that personalized text sticks around forever once it's set the first time in the OS)
None of the login names or passwords I remember work. I checked using a boot DVD with the "Reset Password" utility, but the only user it sees is "System Administrator (root)".
I can think of 2 options from here, but I'd like advice, or another option. One...I could somehow force Setup Assistant to run (how?), create a new administrator, and then do...some process to get back the one user setup I care about (my mom...her files, etc)? 
Or two...I'm not a COMPLETE idiot with Unix (but close)...could I find an old, working Netinfo db and restore it and fix things that way?  I did that years ago, following instructions. I don't know if there is a working Netinfo around though.  In single-user mode I tried "ls" while in /var/backups/ and saw nothing at all.
The history of how/why I did the Install:
My mom's system freaked-out and crashed hard during normal operation (she was just launching AppleWorks)...subsequently all attempts to boot left it at a completely black screen with a single white cursor block in the upper left. No prompt though, and unresponsive to anything I typed, so I wasn't in a normal Darwin. The only way it could be powered-down was to hold down the power key for 10 seconds.
I tried various things...reset PRAM, used "Disk Utility" from a boot DVD (it found no disk problems...though Repair Permissions refused to run, it kept losing connection to the HD), Safe-Booting (which didn't work, it hung with a blue screen, gray Apple logo, no spinning gear), etc. Nothing worked. Booting in verbose mode did go part way, then it stopped with some kind of disk I/O complaint.  I forgot to write it down. My guess, since disk repair found no disk problem, that an OS file was corrupt, and trying to read that resulted in an I/O error.
So I did an Archive & Install with "preserve users".  All seemed to go ok. Until I tried to login.

Answer 1

I followed the steps, the new accounts are there, but they aren't working properly. The primary account worked ok once.
Based on the behavior of 2 accounts (primary admin, + my mom's), even under Safe Boot, it seems like there's something that's failing during login that causes all attempts to login to succeed partway, then crash, and throw me back to re-login.
What happened: I had reset the Netinfo, & created a first admin matching before. After a long time, I got a normal desktop (& it had the desktop icons & Dock layout of the previous primary account).  I created the next 3 users (there were no gaps), and then set it to auto-login to my mom (standard user).
If I Safe Boot so I can try logging-in as the original admin, I get a menubar, a customized Dock (with an odd, empty white square in place of one of the icons), and a spinning beachball against an empty desktop for a while, then it drops me back to the login screen. Same thing if I try my mom's account while Safe Booted.
I have a 2nd admin account, if I try that while Safe Booted, I get a menubar, empty desktop, and an endless spinning beachball. I have to hold down the power key to shutdown.
I tried holding the shift key immediately after login (disable startup items) to see if that helps, but it didn't. Doesn't even seem to work right, because when I boot normally to auto-login to my mom's account, even with shift, her startup item is still launching (a simple app that timestamps a file).
If I don't Safe Boot...it does auto-login to her account, I get a beachball, it slowly builds her entire desktop back just the way it used to be (desktop icons, customized Dock)...then it crashes to a blank blue login type screen and tries all over again, endlessly trying to login, crash, try again. I have to use the power key to force a shutdown.
Force Quit (via the keyboard) never helps in any of the situations, I get no popup window.
I did use Disk Utility again to see if it repaired anything, but all it fixed were a few permissions, which didn't change anything.
What next? What would you suggest now?  They're almost working. Is there a log I can examine in single-user mode that would tell me what's failing during login? Should I reset the Netinfo db again and re-create users? Do I need to install again? Preserving or not-preserving users?