Easy fix: Audit a random selection of affiliate referrers by checking for the affiliate code in the actual source of the page. If it isn't there, either disable

Easy fix: Audit a random selection of affiliate referrers by checking for the affiliate code in the actual source of the page. If it isn't there, either disable that affiliate account or check more of that account's referrers, denying credit for any pages that don't contain the affiliate code.