I pushed the reporting and webforms dll up to our web server but the reportviewer does not render correctly like it is missing image resources so I pushed the resx up to the server as well. Still no luck. It is as if a css is missing. see the attached screenshot.
You can also check with Fiddler or other proxy tool the reason for the failure of the Telerik.ReportViewer.axd handler to serve the resources (images) to the viewer.