Cannot create a Date field with JQuery popup

This issue arose sometime this week in the -dev version... when creating a date field, and selecting the "text field with jquery pop-up calender" widget, I get this error:

    * warning: array_intersect() [function.array-intersect]: Argument #2 is not an array in path_to_my_site/modules/date/date/date_admin.inc on line 57.
    * The Date Popup widget will not work unless granularity includes year, month, and day.

The default granularity is year/month/date/hour/minute, and all I did was deselect hour/minute (all other options left as default)
PS I reselected hour/minute and still get the error.

Note that fields created with older -dev versions that included the pop-up are working fine (display, accept input, filter as expected)