Index: wp-admin/css/themes-rtl.css
===================================================================
--- wp-admin/css/themes-rtl.css	(revision 37158)
+++ wp-admin/css/themes-rtl.css	(working copy)
@@ -795,7 +795,7 @@
 	clear: both;
 	min-height: 330px;
 	position: relative;
-	right: auto;
+	right: auto !important;
 	left: auto;
 	top: auto;
 	bottom: auto;
Index: wp-admin/css/themes.css
===================================================================
--- wp-admin/css/themes.css	(revision 37158)
+++ wp-admin/css/themes.css	(working copy)
@@ -795,7 +795,7 @@
 	clear: both;
 	min-height: 330px;
 	position: relative;
-	left: auto;
+	left: auto !important;
 	right: auto;
 	top: auto;
 	bottom: auto;