Win Vista Home Prem and Favorites

Could some one please tell me -when I open my favorites from the star icon on
the toolbar I click a site on list of favorites,the list then stays open
and the name appears on the bar
to the right of the favorite and organize favorites icons but does not
open.I have to click to close the favorite list and click again on the name
of the site to open it.
This started today and have no idea why
Thank you