Date format for date input component

Hi,
how it works Date Format property associated to Date Input Component?
I tried this:
1) define a Date Input Component and set it to my_param_date parameter (value = 01-01-2013)
2) set Date Format property to 'mm-dd-yyyy'
3) when I preview the dashboard and select "11-18-2013" from data picker the value into the displayed value is "11-18-20132013" (year repeated twice!)

Hope in your help.
Thanks!