i think i got a similar problem. if i use that format sometimes it show always the same day for all the month, such as 26 26 26 instead of 1 2 3 and so on. and every 2 times i click on the input field and the calendar show up, it goes 1 year up as deafult date to show.
I'm not sure about that, but it seems to me the problem is that the input field is formatted as %d/%m/%Y, but when reopening the calendar it read as if it was the other format %m/%d/%Y switching month and day. (so i suppose the year problem depend on this too, if the day is > 12)
PS: i tried opening and closing the calendar with the date 08/04/2010 and even if i close the calendar with the X without choosing a date it changes the old one with the now selected date, causing the continuous switch between the 8 of april and the 4 of august. maybe it was better if on closing without choosing a date it doesn't change anything