namespace or class could not be found (ASP.NET WebSite "project")

I am currently trying to cleanup a bit of a corporate website that I inherited here. I managed to clean up most of the errors in the website but something is still up here. I have one masterpage that have this code : ``` using System; using System.Data; using System.Configuration; using System.Collections; using System.ComponentModel; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; public partial class MasterPage : System.Web.UI.MasterPage { public lists m_listsClass = new lists(); ``` (no it's not a typo the S in lists). Now in App_code I have one class lists.cs ``` using System; using System.Data; using System.Configuration; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; /// <summary> /// Summary description for lists /// </summary> public class lists { public lists() { ``` When I try to build the website in visual studio 2008 I have this error : ``` Error 3 The type or namespace name 'lists' could not be found (are you missing a using directive or an assembly reference?) C:\Users\egirard\Documents\Visual Studio 2008\Projects\iFuzioncorp\iFuzioncorp\Masters\MasterPage.master.cs 23 12 iFuzioncorp ``` Am I missing something ? Also I saw some strange behaviour on the server. Apparently according to IIS7 it is compiling using .net 2.0 (the pool is configured with .net 2) but there are some `"using`" statements that include Linq ... how is it possible to compile the page if Linq is not part of the .net 2 itself ? Just edited with news details on the code itself. No namespace at all everywhere.