[Alsa-user] USB midi device (UM1SX) not listed by aconnect (but works as rawmidi)

[<mes...@gm...>]

hi all,

I've got a strange problem today.
I attach the Edirol UM1-SX, and it doesn't get recognized as an alsa 
sequencer device

I look in /proc/asound/cards and it's listed:
...
 2 [UM1            ]: USB-Audio - UM-1
                      EDIROL UM-1 at usb-0000:00:02.2-3.4, full speed
...
as well as in /proc/asound/devices:
...
 64: [ 2]   : control
 72: [ 2- 0]: raw midi
...


but aconnect -i / aconnect -o do not show it, and also seq24 (or any 
other alsa seq client) does not see it.

still I am able to play it using the raw device:
crw-rw---- root audio 116, 72 /dev/snd/midiC2D0


what happened?
any help is much appreciated

-- 
Federco Ferri