Nitpicky: Italian R

Bear with me, this isn't quite the same as all those other "how do I roll my Rs?" questions. I can roll an R; however, I've noticed that my Italian professor (a native of Florence, if that makes a difference) produces a different sound than I do. It's been a while since I dealt with phonetics, but for lack of a better description, her R roll sounds a little - flatter than mine, or more lateral, whereas mine is sort of rounder and more midline in my mouth.

I guess I have two questions, then: 1) is this a peculiarly Italian sound, and 2) does anyone have any pointers on "flattening" my R? I tried working on it just a little and it actually made my tongue hurt.