It appears that if you configure a datepicker to show multiple months, and the field it's tied to has a date entered, when the picker opens it highlights that day of the month in all displayed months. You can see this happen in the 'Display multiple months' demo, by clicking in the field to open the picker, choosing a date, then opening the picker again. Whatever day you picked is highlighted in all months, so there's no way to tell which one is actually selected.
Is this a configuration problem, a bug, or me misunderstanding how things are supposed to work? I'm inclined to think it's a bug, since it happens in the demo, presumably written by folks more experienced with this plugin than me, and the intended functionality seems pretty straightforward. Checked the bug tracker but didn't see anything, a little surprising for something this clear.
Using UI 1.8.4, jQuery 1.4.2.
Thanks,
Dave