copy Microsoft.ReportViewer.ProcessingObjectModel.dll

When you are trying to build a project with Microsoft Reports you may not be able to build it successfully. You'll be needed to copy the Microsoft.ReportViewer.ProcessingObjectModel.dll to your bin directory of the web project. Following article gives the detailed steps do it.

http://am22tech.com/s/22/FORUM1/default.aspx?g=posts&m=804

cheers
samitha