I got a chance to create a report in SQL Server 2008 and deploy the same in IIS. Below is error recieved.
"The report definition is not valid. Details: The report definition has an invalid target namespace 'http://schemas.microsoft.com/sqlserver/reporting/2008/01/reportdefinition' which cannot be upgraded."
It's a bug in Visual studio and there is a work around provided. Check the below link,
https://connect.microsoft.com/VisualStudio/feedback/details/361103/reporting-services-report-cant-deploy-to-sql-2005?wa=wsignin1.0
Cheers,
Venkatesan Prabu .J
http://venkattechnicalblog.blogspot.com/