related to #1679 fixing glitches on page titles

admin/themes_installed.php

@@ -169,6 +169,7 @@ $template->assign(
 trigger_notify('loc_end_themes_installed');
 
 $template->assign('isWebmaster', (is_webmaster()) ? 1 : 0);
+$template->assign('ADMIN_PAGE_TITLE', l10n('Themes'));
 
 $template->set_filenames(array('themes' => 'themes_installed.tpl'));
 $template->assign_var_from_handle('ADMIN_CONTENT', 'themes');