The radio stations are always disordered and when you press R to change them, they change EXTREMELY fast.
1st: For example, I scroll down from MSX FM to Chatterbox FM. When I scroll up to put MSX FM again, there is a different radio, and if I scroll down again to return to Chatterbox, there is another radio, and this happens all the time I am outside San Andreas.
2st: Scrolling with mouse works well, but pressing "R" in keyboard or "UP"-"DOWN" buttons in GInput (Pad) makes them change EXTREMELY FAST (and disordered, of course).