Hello,
I had a similar issue and it took a 5 minute $95 call to tech support to figure it out. Are you using a leading dot when specifying the login name? Apparantly you have to do this with the Arcserve client now. In other words, login as .admin.organization. This is really stupid, since the Novell client does not require it. It is not mentioned anywhere on the AS web site that I can find, but they still charge $95 to tell you.
Good Luck,
Mike