Originally Posted by newB

Not if the program uses cookies, so the affiliate ID drops from the site URLs, such as the majority of CCBill programs.

Nor programs that make liberal use of canonical links and/or robots files to prevent indexing of site pages containing affiliate IDs, such as PimpRoll.

In such cases, I always encourage using nofollow rel attributes with the site links, since you really have nothing to gain otherwise. However, in most cases this is limited to just the sites and usually not the galleries - though a couple of programs make use of this indexing chicanery on their galleries as well. I wouldn't be a bit surprised if the program to which the OP is referring is one of the latter.