Properties for Date/Time: mouse pointer disappears

Open "Properties for Date/Time" dialog by double-clicking on the clock. Now click "OK" or "Cancel" button. Mouse pointer disappears together with the window.

Sometimes the pointer disappears / stays on every other time you close the "Properties".

If you open the dialog using "Adjust Date/Time..." menu, mouse pointer will not disappear when closing it. Moreover, it may change behavior of the pointer when the dialog opened again by method 1.