Calendar returns 1/1/0001

[mg]

I have a WebForm (C#) with a System.Web.UI.WebControls.Calendar

I first select the current date and it's returned correctly

I then close the WebForm and reopen it

I next select a date other than the current date and it's returned correctly

I then close the WebForm and reopen it

On the third try, if I don't select a date (i.e., if I accept the current date), I get back 1/1/0001

What can I do to correct this problem