Land's End order tracking does not work in Firefox

It is so irritating when companies don't test their websites/don't care if they do not work. I get emails from Land's End when an order has shipped. They have links to a page where you enter your order number and click track, which directs you to a UPS webpage. In Firefox I always get an error "UPS could not locate the shipment details". For kicks I tried it in IE 8 tonight and it works! How annoying.