title: Ajax ScriptManager EnableHistory property not found exception
body: <p>I am getting following exceptions while compiling asp.net web site which uses ajax 1.1. Now the funny thing is that it gets compile sometimes and sometimes not!</p>
  
  <p>1)      Error      330         Type 'System.Web.UI.ScriptManager' does not have a public property named 'OnNavigate'.                </p>
  
  <p>2)      Error      331         Type 'System.Web.UI.ScriptManager' does not have a public property named 'EnableHistory'.                </p>
  
  <p>Some guys suggest to install .net fm 3.5 sp1, this i have alreday installed but does not help.</p>
  
  <p>Please help me out on this.</p>
  
  <p>Regards,</p>
  
  <p>Chandan</p>