When I attempt to scroll down in my Bookmarks pulldown menu, for some reason, the listing starts moving, which prevents me from locking on to the bookmark I seek. It scrolls until the top of the bookmarks list is reached. When I attempt to move below the exposed list, to a target destination I have bookmarked, it automatically scrolls back up. This generally does not happen immediately, but after visiting a half-dozen sites or so, this behavior now always starts. It can be "fixed" (temporarily) by quitting Firefox and restarting but that is too aggravating. Suggestions?