This is weird. I added a brand new Web Application project to my solution in Visual Studio 2008.
Created a master page. Made zero modifications. Created a new we
Your web form shouldn't have all of that markup (like the tag). Since it has a master page, you just start with the content tag. Your aspx page should look like this:
<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Default.aspx.vb" Inherits="WebUI._Default" MasterPageFile="~/Site1.Master" %>
This is the body!
When you're adding a new aspx page make sure to check "select master page" in the "add new item" dialog.