Error on Adding New Server Login

When I tried to add a new login to the server and after assigning DB Roles,
I am getting the error message that the role has been already added to the user. I think this username has already been in the system earlier. It is in the sysuser table. I tried to delete the roles to which this user has permissions. But still I am getting this error. I am not sure where else it is stored. How can I delete this username completely from all Databases and reassign this userid in the server.
Please advise.You're trying to modify system tables...hmmmmmmmmm

What other type of work do you do?

Look at system stored procs sp_dropuser and sp_droplogin|||I am not modifying the system tables. I am trying to add a new user.
But it is not letting me do that as this user already exists in the sysuser table. I executed sp_dropuser 'test' and sp_droplogin 'test'. But still getting the same error when I tried to add this userid and assigned DB roles(I am doing for all 4 DBs at a time).

Thanks
Radhika

error message Only members of sysadmin role are allowed to update .....

Question to those who may have had this same error- it seems that I am not able to delete some of the reports that I have created. This just started happening recently and according to our system admin nothing has changed as far as permissions are concernced. We installed SP2 the other day and I was wondering if this could have anything to do with the error message below

by the way I am a member of the sysadmin group

thanks in advance

km

System.Web.Services.Protocols.SoapException: Server was unable to process request. > System.Data.SqlClient.SqlException: Only members of sysadmin role are allowed to update or delete jobs owned by a different login. Only members of sysadmin role are allowed to update or delete jobs owned by a different login. at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe) at System.Data.SqlClient.SqlCommand.ExecuteNonQuery() at Microsoft.ReportingServices.Library.InstrumentedSqlCommand.ExecuteNonQuery() at Microsoft.ReportingServices.Library.DBInterface.DeleteObject(String objectName) at Microsoft.ReportingServices.Library.RSService._DeleteItem(String item) at Microsoft.ReportingServices.Library.RSService.ExecuteBatch(Guid batchId) at Microsoft.ReportingServices.WebServer.ReportingService2005.ExecuteBatch() End of inner exception stack trace

It looks like you are getting this error because the report has a schedule associated with it and most likely you recently changed the way you connect to the Report Server database. To fix this you will need to set the owner for all of the Report Server SQL Agent jobs to be the user that RS is using to connect to it's database.