I am using chrome 22.0... and following are the steps to reproduce the problem
1. select date in first textbox "22/11/2012"
2. click on the button to see second datepicker
3. choose the date in second datepicker which should be : "15/11/2012"
4. now try to choose any other date in the second datepicker . (it will not show the datepicker again untill you click somewhere and then try to choose the date, this time it will show up the datepicker)