To my knowledge there is no restore function yet. You'll have to restore the files manually. I would suggest backing up via reseller then the other email, conf files manually, that way at least part of it is automated.
Can you share with us what kind of problems you had? I was preparing to use the full system backup function.. but maybe I should wait a little longer with that?
I hate to respond before I do complete research, but I'm so busy right now that it may be a while before I have the time to do the research .
It appears as if two necessary directorly structures weren't properly copied to the backup:
/usr/local/directadmin/data/users
/usr/local/directadmin/data/admin
Note that copying over these directories is only "safe" if you're going to use the same IP#s, and if the old server using the same IP#s is turned off before you restore. Otherwise, when you restore and reboot, both servers will be using the same IP#s, which may make both of them invisible on the 'net.
Several issues have gotten in the way of me completing this and I thank my client who is waiting patiently until I know I can take the time to do it right.
I will post when it's done, and I'm going to try to get it done over this (in the US) three-day holiday weekend.