The CSS rule was too vague and cause the menu items to be
hidden rather than just the first item.
position: relative;
}
-#page-mod-quiz-edit ul.section li.pagenumber:first-child .add-menu-outer .menu :first-child,
-#page-mod-quiz-edit .last-add-menu .add-menu-outer .menu :first-child {
+#page-mod-quiz-edit ul.section li.pagenumber:first-child .add-menu-outer .menu > :first-child,
+#page-mod-quiz-edit .last-add-menu .add-menu-outer .menu > :first-child {
display: none;
}