Not sure which items you’re using in your Widget area, but here’s what I have in my widgets.css:
/* Individual widget title icons */
.widget > h3 i { background-position: -120px -216px }
.widget_archive > h3 i { background-position: -120px -24px }
.widget_tag_cloud > h3 i { background-position: -120px 0px }
.widget_recent_comments > h3 i { background-position: -120px -72px }
.widget_links > h3 i { background-position: -120px -96px }
.widget_pages > h3 i { background-position: -120px -120px }
.widget_recent_entries > h3 i { background-position: -120px -144px }
.widget_meta > h3 i { background-position: -120px -192px }
.widget_categories > h3 i { background-position: -120px -168px }
/* Individual widget title icons, when the parent .widget is hovered */
.widget:hover > h3 i { background-position: -96px -216px }
.widget_archive:hover > h3 i { background-position: -96px -24px }
.widget_tag_cloud:hover > h3 i { background-position: -96px 0px }
.widget_recent_comments:hover > h3 i { background-position: -96px -72px }
.widget_links:hover > h3 i { background-position: -96px -96px }
.widget_pages:hover > h3 i { background-position: -96px -120px }
.widget_recent_entries:hover > h3 i { background-position: -96px -144px }
.widget_meta:hover > h3 i { background-position: -96px -192px }
.widget_categories:hover > h3 i { background-position: -96px -168px }