Hello Andrea.
now the serous reply;
I don't have a U20 so went to the Roland site to find out what it is?
I found a US20 which is in fact a midi device like my GI-10, is the U20 the same as the US20?
What soundcard are you using?
Which version of windows?
Which software are you using for recording?
Did you set up the midi input in the configuration menu?
fred
_________________________
Keyboards/Sound Units: Kurzweil 2600S, Roland VR-760, Acces Virus C, Roland G-800, Akai AX60, Minimoog, Machine Drum, Roland R8-M, mediastation x-76