Lync 2010 - error publishing SQL Reporting HTTP 401 Unauthorised

Problem
When trying to publish Lync 2010 SQL reports to a Windows 2008 R2 / SQL 2008 R2 server.
you receive error "HTTP 401 Unauthorised"

Cause
This is because by Default SQL 2008 R2 / Windows 2008 R2 is set to auto negotiate the authentication method. The problem is, that it will try and use "kerberos" authentication which by design is far more secure, which in turns can cause restrains on certain actions .
Full Details

http://msdn.microsoft.com/en-us/library/cc281253.aspx

Resolution
Force SQL Reporting to use NTLM Authentication.

Use NTLM. NTLM will generally work in cases where Kerberos authentication fails. To use NTLM, remove RSWindowsNegotiate from the RSReportServer.config file and verify that only RSWindowsNTLM is specified. If you choose this approach, you can continue to use a domain user account for the Report Server service even if you do not define an SPN for it.