This happens when the system date is not in the correct format
Most of the time it has to be in MM-dd-yy and your date would have 
been in dd-MM-YY 

This is how you fix it 

Start->ControlPanel
Regional & language Options
click on customize 
select date tab

change Short Date Format to - MM/dd/yyyy

You are good to go. I am not sure if you have to reboot the machine. If it 
dosent work then just reboot your machine.