Comment 4 for bug 745638

Why doesn't USC already know whether you're authenticated? It seems to me that the only time the spinner should start, then stop, then start again, is if you've changed your password on the Web interface -- so USC tries to authenticate with your old password, then puts up the dialog, then authenticates with your new password.

Annoying though it may be, there is some non-zero number of people who will think that they can't enter their sign-in details until the spinner stops spinning. :-)