i am developing a sharepoint webpart using asp.net framework 3.5 and i attempted to use a ListView. but i get the error message: "Unknown server tag 'asp:ListView' in sharepoint 2007".
i have already added the following line to the conrols tag in my web.config and it still will not recognize the ListView:
<add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>

<add tagPrefix="asp" namespace="System.Web.UI.WebControls" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>

What else can i attempt to fix this?
thank you