irishsolar - 9:28 am on Apr 28, 2012 (gmt 0)
I suspect the site is being marked down as an affiliate.
I really don't see this update as being in any way an attack on affiliate websites. If anything I have seen an increase in affiliate sites at the top of the SERPs in several niches I am monitoring.
I don't think Google has ever really targeted affiliate sites per se. I just believe that many affiliate sites are weak and have very little value to offer and this is why they have been targeted in the past - not because of affiliate links but because they were crap sites!