I, too, have the exact same problem. I had it crop up already in early November, when I was still running Backup Exec 9.1. So I tried upgrading to 11D but that did not fix the problem. It definitely does seem to be an authentication and Active Directory related issue, but I work in a small office with a very simple AD structure, and only one GPO.
If there's one thing that seems to be the cause, it's that we added two servers that are DCs running Windows 2003 Server Enterprise Release 2 (that "Release 2" is key here, because someone already suggested to me that adding these servers may cause some security changes in AD), right around the time the problem started.
I am using the Domain's Administrator account as the Backup Exec System Logon Account. It is a member of the local Administrators group of the servers that I am unable to connect to. So, Deepali, sorry, that does not fix the problem.
Let me state what I have got in this scenario:
1. The Backup Exec Server running 11D on Windows 2000 Server with all service packs and updates.
2. The two new servers -- I'll call them A and B -- having Windows 2003 Server Enterprise Release 2. They have Exchange 2003 Server Enterprise installed. They are Domain Controllers. (I have absolutely no problem creating all kinds of selection lists for these servers.) These servers were added to our Domain in early November which is about the same time that this problem started.
3. The two servers that I cannot create a selection list from. I'll call them C and D. They are running Windows 2003 Server Enterprise (but NOT Release 2). They are members of the Domain, but are not DCs. I had been backing them up fine till I started getting Access Denied errors in early November, with Backup Exec 9.1.
It is worth mentioning that when logged as Domain Administrator on the server where Backup Exec is installed, and I use Windows Explorer, I can easily browse to Server C or D and view the shares and the files and folders, without ever being challenged for authentication for access.
Just to round things out (but I don't think it's too important for this discussion), I am backing up two more servers, again with no problems, one running Windows 2000 Server, the other running Windows 2003 Server (not Release 2).
I have tried a push install of RAWS, then I tried a local installion of RAWS, for both C and D. Both times the installations completed successfully, and both times RAWS was successfully telling our Backup Exec server that C and D existed. However, when I would create a selection list, by going to the Job Setup tab and selecting New Selection List, then the Favorite Resources level in the tree, then Windows Systems, then C (or D), I get an hour glass for about 20 s and then the Logon Account Selection dialog box. The top of that box has the text:
Failed to access C.domain.com
Logon Account: System Logon Account
Access is denied.
I can try editing the password for the account, or simply create an alernate account, but that is futile. Plus, the System Logon Account works fine for all our other servers.
So with this error, I cannot get further than seeing the Servers C and D -- I cannot see the drive letters or the shares underneath.
I even tried taking servers C and D off the domain and adding them back on. That did not fix the problem.