Nullable DateTime editor and PropertyGrid interop

I just purchased the editors package so we could use it with the Actipro PropertyGrid that we had purchased a while ago.

I was able to get it working fine but have a question about the nullable DateTime editor. When the PropertyGrid first opens, nullable DateTimes display fine and shows that there is no date or time set. However, once the user either enters a date either by hand or by the dropdown date picker, they can not set the date back to null again. They are able to delete the month, day, year, etc. all individually but if you completely delete a value (for example the month), when you start to edit another component of the date (like the day of the month) the value that you tried to delete goes back to its original setting. Aditionally, Ctrl-A only selects the numbers in the current date component that you are editing, so that does not help us either. We really need a way to revert the DateTime back to null in the event of an accidental input.

If it helps, our property editors are set up like so on a single instance of the PropertyGrid:

<propgrid:PropertyGrid.PropertyEditors>
                <propgrid:PropertyEditor ValueTemplateKey="{x:Static propgrid:BuiltinEditors.DynamicStringValueTemplateKey}" />
                <propgrideditors:DateTimePropertyEditor />
                <propgrideditors:NullableDateTimePropertyEditor />
</propgrid:PropertyGrid.PropertyEditors>

 Am I missing something on the control or perhaps a property setting?

Thanks,

Evan Phillips