Page goes to error after click before page fully loaded.

Hi all ,
 When user cliick on the control before page fully loaded it goes to error page. 
Following is the trace.
Execution Error
Invalid postback or callback argument.  Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page.  For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them.  If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.
  at System.Web.UI.ClientScriptManager.ValidateEvent(String uniqueId, String argument)
  at System.Web.UI.Control.ValidateEvent(String uniqueID, String eventArgument)
 &nb ...