onControlLoad is undefined

Hi, I'm working on getting this to work with forms authentication and using the code behind method of loading the FileVistaControl. I'm using Visual Studion 2008. When I run the application from Visual Studio it works correctly. However, when I publish my application up to my Windows 2008 R2 server with IIS7 and try to run the application, I get "'onControlLoad' is undefined" pointing to default.aspx Line 18 Char 1. This appears to be happening when the following line executes:

PlaceHolder1.Controls.Add(fileVistaControl);

Any ideas what I'm doing wrong?

Nathan.

I think I have solved this but the answer seems non-intuitive. I had to enable anonymous access to the 'FileVistaControl' folder in IIS.

Nathan.