Index: wp-admin/customize.php
===================================================================
--- wp-admin/customize.php	(revision 32964)
+++ wp-admin/customize.php	(working copy)
@@ -1,4 +1,4 @@
-<?php
+	<?php
 /**
  * Theme Customize Screen.
  *
@@ -26,10 +26,13 @@
 if ( ! $return ) {
 	if ( $url ) {
 		$return = $url;
-	} elseif ( current_user_can( 'edit_theme_options' ) || current_user_can( 'switch_themes' ) ) {
-		$return = admin_url( 'themes.php' );
+	} elseif ( 
+		( current_user_can( 'edit_theme_options' ) || current_user_can( 'switch_themes' ) ) ||
+		( isset( $_SERVER['HTTP_REFERER'] ) && false !== strpos( $_SERVER['HTTP_REFERER'], admin_url() ) )
+	) {
+		$return = admin_url();
 	} else {
-		$return = admin_url();
+		$return = home_url( '/' );
 	}
 }