I never had problems but last time I went back I noticed a lot of people would speak to me in Spanish before I would speak to them, which I found strange. However, I made an effort to speak more nuetrally. I would also never use vos! I studied in Guatemala before coming here, and in central america vos is considered to be very informal and means a very close relationship, like brother-sister, compañero (same political organization), lover, best friend, etc. Not something you want to use when you just meet someone.
Just like in Argentina Ud can mean you are pissed off at someone, that you are putting distance between yourselves, whereas in other parts of Lat Am that is not the case. My husband only uses it when he is really mad at someone or he is talking to a cop.
On another note, I had a really hard time understanding Chileans and I don´t think they understand me.