Insufficient rights to deploy reports in ax 2012 from Visual Studio.

Whenever i try to deploy the reports i am getting the error as

The deployment was aborted. You do not have privileges to deploy to server: nds236. For deployment, you must have administrative rights to the SQL Server Reporting Services (SSRS) server. Contact your administrator to deploy. C:\Program Files (x86)\MSBuild\Microsoft\DynamicsTools\Microsoft.Dynamics.Framework.Design.Reporting.Modeling.targets

I gave the rights to my id on reports server as system admin and system user but then too the same error persists ,I tried to run as admin for Visual Studio which worked for the day ,but when i tried to do the same the other day it gave me the error as

The “GenerateRdlTask” task failed unexpectedly.

Microsoft.Dynamics.AX.Framework.Services.Client.UserSessionServiceException: A call to SSPI failed, see inner exception. —> System.ServiceModel.Security.SecurityNegotiationException: A call to SSPI failed, see inner exception. —> System.Security.Authentication.AuthenticationException: A call to SSPI failed, see inner exception. —> System.ComponentModel.Win32Exception: The target principal name is incorrect

Does anyone have any clue why is this thing occuring .any help is appreciated,

Thanks,

Vikas Mehta.