midi not detected

Hi.

First of all: FANTASTIC product. I had never heard of it, found out just now! Keep up the good work!

Now for my problem: MIDI doesn't seem to work on my setup:

MuseScore 0.9.5 on winxp sp3 with the ROMI/O by ESI usb midi interface. Installed drivers for the usb midi interface, and it works perfectly in finale (2009), where it's named: "1-RoMI/O MIDI".

I installed PmDefaults, and it sees the following devices:
Default input: 1 [MMSystem]
Default output: M [MMSystem]

When playing my keyboard, the green light in PmDefaults flashes, so I guess this bit works also.

However, in MuseScore nothing happens when I play my keyboard. (and yes: the midi input button is 'on')

Any ideas where the problem could be?