problem with state/province when create account

[win8win]

in sign up page,
if I didnot select a state/province from dropmenu,and click "submit",
it won't show the following message "Please select a state from the States pull down menu",
but "If you already have an account with us, please login at the login page".
what is worse,all filled content were cleaned up,so have to fill all again
what is wrong?
what should I in order to let show the right warning message?

[win8win]

my solution for it is to use normal backup then do again.