I got a problem with reporting services, running local rdlc files on the 2005 version.
I have in the HTML a report viewer set to run locally as follows :
Had the same problem. Took a while to figure out for me but it turns out I accidentally new'ed the reportViewer control myself so I lost what the Visual Studio Designer had created for me when I designed the form and that is why the reportviewer control kept coming up blank - I never set any properties on the Visual Studio Designer's ReportViewer object.
Silly mistake but took quite some time to figure out.