I’ve used the Yahoo! Toolbar before, where are my customized buttons?
Older versions of the Yahoo! Toolbar required you to sign-in with your Yahoo! ID to see your customized buttons.
With the latest version of Yahoo! Toolbar, your customized buttons are now available to you without the need to sign-in with your Yahoo! ID.
There will be a migration option to inherit all your old settings automatically. Please check http://toolbar.yahoo.com for updates.