401 unauthorized from Reporting Services 2008 R2

I used method 2 here to resolve this...

http://support.microsoft.com/default.aspx?scid=kb;en-us;896861

Method 2: Disable the loopback check (less-recommended method)

The second method is to disable the loopback check by setting the DisableLoopbackCheck registry key.
To set the DisableLoopbackCheck registry key, follow these steps:

1. Set the

   DisableStrictNameChecking

   registry entry to 1. For more information about how to do this, click the following article number to view the article in the Microsoft Knowledge Base:

   281308 Connecting to SMB share on a Windows 2000-based computer or a Windows Server 2003-based computer may not work with an alias name

2. Click Start, click Run, type regedit, and then click OK.
3. In Registry Editor, locate and then click the following registry key:

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa

4. Right-click Lsa, point to New, and then click DWORD Value.
5. Type DisableLoopbackCheck, and then press ENTER.
6. Right-click DisableLoopbackCheck, and then click Modify.
7. In the Value data box, type 1, and then click OK.
8. Quit Registry Editor, and then restart your computer.