On OS X, on first load/focus if you enter a date manually then press the "Enter" key (the one on the numpad), of a full keyboard OR the "Enter/Return" (MBP for me) key on a laptop, the date will return to current date.

So if I go in and put in 12/12/2000 it'll return back to 12/31/2008. If I change the date through the date picker, say I change it to 11/12/2008 then try to do 12/12/2000 and press either one of those keys it'll return back to 11/12/2008. But if I press the "Return" key on a full keyboard, neither of the bugs happen.

This happened on Opera, FF2, FF3 and Safari.