I found the same problem but something different,

That was..

When Start new Web Project with Default File. I go to the code part that has no NameSpace any where.

But instead of that I found Partial Class Concept in the main Class that was Default.cs file : - Public partial default{.....}

Now VS2005 has Spnipet and Surround Concept I try to add all code in Namespace with Surround concept.

Then after i compile the project that give me error message : -

1) App.default.aspx.GetTypeHashCode() : No Stutable  Method Found to override.with app_Web_qjxrz39q.o.cs

2) App.default.aspx.ProcessRequest(System.Web.HttpConcext): No Stutable  Method Found to override.with app_Web_qjxrz39q.o.cs 

3) App.default.aspx.does not impliment interdface member: System.Web.IHttphandler.IsReusable : app_Web_qjxrz39q.o.cs 

 Whenever I remove namespace it complile Successfully.

So What would the problem ? for that.

How to Start project with Namespace..in Web Application. in Visual Studio 2005.??? 

 If You have some idea regarding this please post the answer.