04ac3695_se_Notes___Amazon_Web_Services__Issue
[Description] MerchantId is not used in books, music, classical, video, wireless, DVD, communities, wishlists, Target, and all international stores. MerchantId cannot be used as a filter for any of these groups. Doing so might lead to unexpected results, such as items being sold by some merchant other than the one specified by the MerchantId. [Impact] Do not use ItemSearch requests that use MerchantId. [Issue] 
MerchantId does not always filter search results.
Release: Amazon E-Commerce Service on 2007-07-23 : Release Notes : Amazon Web Services