Unknown server tag ‘asp:ScriptManager’.
in the web.cofig insert this:
<controls>
<add tagPrefix=”asp” namespace=”System.Web.UI” assembly=”System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35″/>
<add namespace=”AjaxControlToolkit” assembly=”AjaxControlToolkit” tagPrefix=”ajaxToolkit”/>
</controls>
Enjoy

Exactly what I was missing. Thanks
btw. it’s enough to add just
hm…. where is the code in my comments? I was trying to say that’s enough to add just the line with tagPrefix=”asp”