What is different in the ASP.Net 2.0 code behind model?
In 2.0, the code-behind class is now a partial class WITHOUT the declared member variables representing your serverside controls. These members variables will instead be declared in another partial class that will be generated automatically by the runtime. Here is an article from ftp online: The New ASP.NET 2.0 Code-Behind Model
that talks about this change in detail.