Clicking on tab while looking at datetime property causes property to freeze

Description

Steps to reproduce:

1. Add a DateTime property to a page type:

 public virtual DateTime CustomDate { get; set; } 

2. Create a new page with that property.
3. Edit the property.
4. Press the "tab" button.

Expected:
It switches to the another property or object.

Actual:
The Datepicker does not respond to updates.