please help - "Compilation Error"

why is this happening?

Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: BC30456: 'CreateResourceBasedLiteralControl' is not a member of 'ASP.default_aspx'.

Source Error:



Line 1: <%@ Register TagPrefix="SSD" TagName="background" src="background.ascx" %>
Line 2: <%@ Page Language="vb" Debug="true" Explicit="True" CodeBehind="default.aspx.vb" AutoEventWireup="false" Inherits="_default" %>
Line 3:


Source File: C:\Inetpub\wwwroot\IISapps\reg\default.aspx Line: 1