Access Denied when tyring to join or un-join the domain

We recently had one of our Windows 2000 consoles crash.  No problem, we have others just like it so I syspreped one of the functioning ones and made an image.  However, when I brought the syspreped box back online and ran through Windows setup etc I couldn't join the domain.  We keep getting "Access is Denied" errors when trying to join.  AD would show the system correctly, but then disable it after the first login attempt.

 So we tried applying an image of a non-syspreped console to the box, then with the network unplugged we tried to move the computer to a workgroup and we get "Access is Denied".

In all my experience, limited as it may be, with no network (i.e. no domain controllers), logged in as the local admin I should be able to dis-join the domain, correct?  

All of the Access is Denied errors are leading me to believe that there is a permission problem somewhere, but I'm not sure where.  We have even tried throwing a non-sysprepped image on the box, then changing the name without ever dis-joining the domain.  The name is changed in AD but the I get the following error: "The system  cannot log  you on to this domain  because the system's  computer account  in its primary domain is missing or the password on that account is incorrect"  and using nltest /sc_query:domain results in an "Access is Denied" error.

Any ideas what i can try next?

Thanks for any help you can give!
-Aron