I was faced with a new (to me) problem today. As part of testing of a Silverlight application that has SSRS based reports, the client reported an issue on some machines. They are able to print a report, but clicking on export or print button was causing issues. The actual error reported from Silverlight application was “Unable to load client print control.” Apparently this is a know issue caused by a Microsoft issued patch a few month ago. Here are the details of the issue and links to patches to address it: http://blogs.msdn.com/brianhartman/archive/2008/11/05/client-print-fails-to-load-after-microsoft-update-956391.aspx
Here is a direct link to SQL Server 2008 Report Viewer redistributable package: