I have to say that my observations at EZE showed me it would seem that they do tend to 'pick' on Argentine passport holders/residents more than they do foreign nationals.

Rather OT but when we witnessed customs carrying out a clearance check on our containerised belongings at the port it consisted of them taking three boxes from the front of the container,opening them taking a quick look,couple of questions and signatures and it was free to go. All done very professionally quickly and smoothly without any fuss. ^

If I'd known it was going to be that easy I would have packed a lot more duty vulnerable items.