Index: wp-admin/css/ie.dev.css
===================================================================
--- wp-admin/css/ie.dev.css	(revision 21547)
+++ wp-admin/css/ie.dev.css	(working copy)
@@ -273,7 +273,8 @@
 	margin: -3px 0 4px;
 }
 
-#widget-list .widget {
+#widget-list .widget,
+.feature-filter .feature-group li {
 	display: inline;
 }
 
Index: wp-admin/css/wp-admin.dev.css
===================================================================
--- wp-admin/css/wp-admin.dev.css	(revision 21547)
+++ wp-admin/css/wp-admin.dev.css	(working copy)
@@ -7698,8 +7702,8 @@
 }
 
 .feature-filter .feature-group li {
-	display: inline;
-	float: left;
+	display: inline-block;
+	vertical-align: top;
 	list-style-type: none;
 	padding-right: 25px;
 	width: 150px;