Hi George,
Did you do a complete uninstall of the Silverlight Viewer beta 2 release, before installing final?
Some other things to check for:
- Did you remove both the Builder and Apps folders in the inetpub/wwwroot directory (in case they did not get removed by the beta 2 uninstall)?
- Ensure that both the Builder and Apps folders are no longer registered with IIS?
Hope this helps,