Also have many stamps and my last trip was a bit unnerving for me at EZE: immigration. When entering, the agent took off and I guess conferred with someone. After about five minutes or so she returned and gave me a ninety day tourist stamp. Did not say anything. When departing about three weeks later, same deal, agent took off and returned in about five minutes and gave the exit stamp. Asked if everything is OK and she said "no problems." Know she made some entries into the computer, what they were is a anyone's guess. The exit thing kind of baffled me, in Argentina for 22 days. My best guess is they keep a running total for the days spent in Argentina. Have never over stayed or even come close. Just make a lot of trips to Argentina. Stay for about three weeks and away for a month or so.