Unfortunately, I have run into a difficulty in following your instructions.
Starting at the screen that says:
"
Yahoo! Account Security has identified a possible risk to your account.
We recommend that you change your password as soon as possible. Some Yahoo! services, such as Yahoo! Messenger, may not work until you change your password.
If you choose not to change your password at this time, please note that you are leaving your account and information at risk.
Continue on to Yahoo!
Current Password
New Password
Password Strength
Re-type New Password"
I click to continue, then log into Yahoo, but it immediately logs me out and presents the
"Yahoo! Account Security has identified a possible risk to your account" screen again.
So, I have no opportunity to configure full session SSL.