ASP.NET “Could not Load Type” just on Server

[TheOriginal]

I have a ASP.Net 3.5 host. I just opened a new, C# Web project in visual studio 2010. I changed customerror to None and delete authentication mode line and select None in server control panel. Project works on local machine and says Hello World when I build and deploy in to server via FTP, I get an error it says Could not Load Type '_Default'<%@ page language="C#" autoeventwireup="true" CodeFile="Default.aspx.cs" inherits="WebApplication._Default" %>my namespace is WebApplication and in class name is _Default Default.aspx.cs, It works when I start in ISS, but It cannot start on server.