I think i'm older than you. I learnt in the school they were different letters, and also I remember when they were removed at the beginning of 90's

That's funny; I spent several hours of class time trilling r's to make sure we pronounced "carro" correctly, and repeating a 30 character alphabet.

rr not being its own letter has no bearing on if you can pronounce carro correctly, just like saying church right has no bearing on if c and h are two letters or ch is a single letter.

What can I say? Apparently the textbook was wrong.

I'm afraid that I have to add my voice to the list of people raised in Spanish speaking countries prior to the 90s who was VERY clearly taught that rr was a separate letter.

This is what I recall from my childhood: http://img.docstoccdn.com/thumb/orig/113964108.png