Ahhhh thanks everyone for posting. Really helpful although the offending AO node, may not be what you thought it was.,

In Scooby Dooh fashion, I fear I must now unmask the offender.
It was mr AO Map!
You see Mr AO Map was in a sneaky relationship with Diffuse Map via the Mix Node.
(thanks to a very interesting albeit less theatrical post from caisson in the BSDF thread)

That method from Caisson is something I always do if my texture set comes with an AO map simply because I don't like maps going to waste. It'd really be superfluous otherwise but you can use it to add to you diffuse map.

I habitually set the diffuse map gamma to 2.2 and the others to 1. It's become a bit engrained  to be honest but it's also because I like to get rid of issues before they happen rather than go back and look for a culprit.

shvrdavid you really have got that cling film to look good there.