Text field instead of date fieldon the registratio

I use CB 1.7 with Joomla! 1.6.5.
In the registration form, I added some extra fields, including date of birth.

However, when I look on the page, the field is not a birth date field, but a TextField. In "Field Management" is to indicate that the field is a date. When I edit a user I see a 'date field'.

Is there a solution? Thanks for your answer!

Confirmed for 1.6.6.
1.7.0 no problem