My ASP.NET MVC2 application is developed using 1. VS 2010 2. Linq To SQL for Models

Here is Call controller code:

namespace CallTrackMVC.Controllers
{
    public class CallController : Controller
    {
        private CallTrackRepository repository;

        public CallController():this(new CallTrackRepository())
        {
        }

        public CallController(CallTrackRepository newRepository)
        {
            repository = newRepository;
        }
}
}

Error on IIS7 when browsing the Call Create page is

NullReferenceException: Object reference not set to an instance of an object.]
   CallTrackMVC.Models.ExecOfficeDataContext..ctor() in C:\ClearCase\rartadi_view\STS_Dev_TEST\CallTrackMVC\Models\ExecOffice.designer.cs:71
   CallTrackMVC.Controllers.CallController..ctor() in C:\ClearCase\rartadi_view\STS_Dev_TEST\CallTrackMVC\Controllers\CallController.cs:16

[TargetInvocationException: Exception has been thrown by the target of an invocation.]
   System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck) +0
   System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache) +117
   System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean skipCheckThis, Boolean fillCache) +247
   System.Activator.CreateInstance(Type type, Boolean nonPublic) +106
   System.Web.Mvc.DefaultControllerFactory.GetControllerInstance(RequestContext requestContext, Type controllerType) +102

[InvalidOperationException: **An error occurred when trying to create a controller of type 'CallTrackMVC.Controllers.CallController'. Make sure that the controller has a parameterless public constructor.**]
   System.Web.Mvc.DefaultControllerFactory.GetControllerInstance(RequestContext requestContext, Type controllerType) +541
   System.Web.Mvc.DefaultControllerFactory.CreateController(RequestContext requestContext, String controllerName) +85
   System.Web.Mvc.MvcHandler.ProcessRequestInit(HttpContextBase httpContext, IController& controller, IControllerFactory& factory) +165
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +80
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +389
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +371

Code in Global.asax is

 protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();
        RegisterRoutes(RouteTable.Routes);
    }

Any suggestion would be a great help.