just booked 2 tickets Iguassu to Rio (WED) / Rio to Buenos Aires (SAT) for September .... called on Monday or Tuesday this week and got the confirmed booking within 12 hours ...... I used the Tokyo office, but that shouldn't matter ....

I just need to buy a ticket from EZE to Iguazu now, since I couldn't include a stopover en-route to Rio .....

good luck ! It is frustrating, since you have to wait and then start over again. I guess we got lucky ......