When in profile preview mode date/time displayed with simple text field.

When viewing a date field (e.g Activity Date) via the new Profile editor preview mode (from survey). The date field displayed as a standard edit control. This seemed to happen after I re-arranged the fields on the screen (changed the display order). The behaviour reverted to using the standard date picker after I removed and re-added the date field from the profile.
Save, Edit, Preview.
You can reproduce this problem by the following actions:
From the Configure Survey screen.
Click 'create'
Name the new profile
Drag Activity Details to the form
Drag Activity Date to the form
Click Save
Click Edit
Click Preview - the date field is displayed without a date/time picker.

When trying to reproduce the problem by adding/removing the date field the system go into the state where I could not save the profile from the preview mode due to an error: 'The field was not added. It already exists in this profile'.