small update for previous installation.

in cataog/rss.php file

-Find:
header('Content-Type: application/xml; charset=utf-8');
header("Last-Modified: " . tep_date_gmt($last_modified));

-And replace with:
header('Content-Type: application/xml');
header("Last-Modified: " . tep_date_raw($last_modified));

no file...

More...