On Sunday, 23 January I flew from Austin, Texas, USA to Capital Federal EZEIZA, Argentina arriving Monday morning, 24 January. When I arrived at the Austin, Texas (AUS) airport, the automatic check-in machine rejected my entry because my return ticket was more than 90 days out (return is 29 July). The agent then took over with my check-in. The United agent asked for my trip documentation visiting other countries since I could stay in Argentina only 90 days. I explained that I would be going to Uruguay during my trip but had no confirmed or paid for travel documentation. The agent then called another agent over . . and they called a supervisor. The net result is that United documented my electronic file that I had been cautioned that Argentina may not let me into the country since my return flight was more than 90 days out. By documenting the file, United could then not be held responsible if I were denied entry into Argentina. I already had the Argentina reciprocity fee entry form (good for 10 years or until my passport expires) pasted into my passport (paid it last year -- USD $140). There was no problem upon arrival at Ezeiza . . .normal entry. My trip was a bit more complicated because I had booked frequent flier miles on Continental and was switched to United (merger results). Continental had not questioned when I did this last year. Perhaps a change in policy due to the merger? Hope this helps.