Binding a wrapper class on Ajax POST

Question

I have a ASP.NET MVC wrapper class that wraps a List containing ViewModels:

public class ScheduleContainerViewModel
{
    public List<SchedulingViewModel> Items { get; set; }

    public ScheduleContainerViewModel(List<SchedulingViewModel> items)
    {
        Items = items;
}

SchedulingViewModel contains a Schedule object and a Users object.

ScheduleContainerViewModel is eventually passed to a PartialView. This PartialView is called via Ajax to populate a div in a View. The model for the PartialView is ScheduleContainerViewModel and the model for the View is a Job.

The Ajax GET works great. When I try to POST it, however, the Controller is never called and I get a 500 server error. Here's some of the XHR data being POSTed:

It seems to me that List Items is being passed, containing SchedulingViewModels and their associated Schedules, but maybe not?

There are three relevant methods in the Controller. Here are their signatures:

public ActionResult ScheduleJob(int? id)
public ActionResult Table(int? id)
[HttpPost]
public ActionResult Table(ScheduleContainerViewModel cvm)

ScheduleJob loads the initial View, which calls [HttpGet] Table to load the PartialView. Finally, [HttpPost] Table is the one being POSTed to. Why can't the model binder see the data being passed to it in the XHR?

My only guess it that it's because the model used by the View called by ScheduleJob is different than the one being POSTed to [HttpPost] Table.