Method not found: 'Void Microsoft.Reporting.WebForms.ReportViewer.Reset()'

Hello,
I'm at my wit's end with this one, so any assistance or guidance you might be able to offer would be much appreciated, please
My ASP 2.0 Web application has a ReportViewer control which displays client reports. The control worked fine (both in development and production), until I decided to start dynamically changing the RDLC at runtime (based on user input) using the ReportViewer.Reset() method. This method works fine on my development computer, but on our webserver it fails with the following error:
System.MissingMethodException: Method not found: 'Void Microsoft.Reporting.WebForms.ReportViewer.Reset()'.The closest thing I've found to an explanation is this, however their explanation (of differing .dll ver ...