When fetching multiple topseller from one browsenode, ordered by salesrank, some items don't have specific properties. Zend_Service_Aamazon does not check for them, and tries to access them even if they are not existent. The result are many notices on the front page, which are not nice. The two different error message I get are:

Notice: Trying to get property of non-object in /var/www/projects/sparia/library/Zend/Service/Amazon/SimilarProduct.php on line 45
Notice: Trying to get property of non-object in /var/www/projects/sparia/library/Zend/Service/Amazon/Offer.php on line 50

The first one, regards to the xpath search for similar products, while the second one is the availability of an offer, which is not always present.