Is it possible that this issue affects not only the CheckBox but also the DatePicker?
I just played around with the Grid control and some other Kendo elements within the grid using Editor Templates.
Ordinary text boxes, numeric text boxes and DropDownLists work fine, but the DatePicker and the CheckBox do not.
In both cases, values disappear when switching into edit mode (InLine).
Furthermore, values get lost when switching back into read mode.
This indicates that bindings obviously do not work in any direction.