Spencer,
Just a quick suggestion - try using your domain name in the pop-up, for example:
'yourdomain\root' (no quotes)
instead of just
'root'
I think I ran into this the other day, and that fixed my issue.
All the standard stuff at the bottom of Darrell's HOW TO apply, so please make sure you have double checked those, ie making sure your workgroup name on the client is not the same as the domain PRIOR to joining.
Good luck, and let me (us) know how it goes...I've been dealing with Samba/Win2k issues for several months, so I know the feeling of frustration.
Regards,
Patrick