Calendar Control: Problem while deleting date manually

Hello,

I am using ASP.NET AJAX Calendar control to select date . Following is my code:

 <asp:CalendarExtender ID="CalendarExtender1" runat="server" Format="dd/MM/yyyy" 
        PopupButtonID="ibtnCalender" TargetControlID="txtDate">
        </asp:CalendarExtender>

In the text box my date is also displayed correctly. Say : 29/11/2010 . The problem i am facing is when i Delete '2' from '29' my date becomes 91/12/010 ie.. it shifs position to left by one point. I dont want this to happen. When i delete '2' my date should be _9/11/2010 or else if i delete '1' from '11' my date should be 29/_1/2010 ie. it should not sift one position to left....PLEASE HELP ME OUT HOW TO DO THIS??

THANKS!!!

Best Regards,
Rohan Laghate