I hold German and Argentine passports and I once entered Argentina (being born there) on the German one because the Argentine one was no longer valid. No problem. I already entered a number of countries on both passports, including Russia, Syria, Switzerland, Brazil, no problem at all. The important thing - as I was told - is to enter and exit the country on the same one.
The interesting thing about the Argentine documents is that they all have the same number...it is your personal number and it remains the same, not matter how many passports you've had. If that was the case (and - before I am accused of praising something Argentine- I am not implying Argentina is being smarter in this case) maybe this number (plus nationality on the passport) could be used to identify the person and there wouldn't be any chance of double names like described in other posts. What's the point in changing the number of the passports?
The interesting thing about the Argentine documents is that they all have the same number...it is your personal number and it remains the same, not matter how many passports you've had. If that was the case (and - before I am accused of praising something Argentine- I am not implying Argentina is being smarter in this case) maybe this number (plus nationality on the passport) could be used to identify the person and there wouldn't be any chance of double names like described in other posts. What's the point in changing the number of the passports?