Hi
I am using RadGrid,  and I have a problem with the "Edit,Update,Cancel" 'Delete" columns.
Everything is working fine if the button styles are set to 'LinkButton' or 'Pushbutton'

However as long as I change the button style to "Imagebutton", and clicking "Edit" or "Delete " button the application crashes.
with exception like below:
 
"Microsoft JScript runtime error: Sys.WebForms.PageRequestManagerServerErrorException: 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."

And everything stopped in the file "MicrosoftAjax.debug.js" line 4723
......................................
            _this._clearTimer();
            _this._responseAvailable = true;
            try {
                _this._webRequest.completed(Sys.EventArgs.Empty);
            }
            finally {   ------------------------------------------------------------------------------->stops here
                if (_this._xmlHttpRequest != null) {
                    _this._xmlHttpRequest.onreadystatechange = Function.emptyMethod;
                    _this._xmlHttpRequest = null;
                }
            }
        }

Wondering whether some settings need to be done, thanks if anyone can help me.